JP6225745B2 - Power storage device - Google Patents

Description

  The present invention relates to a power storage device.

  A secondary battery as an example of a power storage device includes, for example, an electrode assembly in which electrodes are stacked via a separator, and a case in which the electrode assembly is accommodated. Further, there is known a case having a pressure release valve that is opened when the pressure in the case exceeds a predetermined opening pressure (see, for example, Patent Document 1).

Japanese Patent No. 4881409

  Here, a resin part having a relatively low melting point may be accommodated in the case. In this case, when the temperature in the case becomes excessively high, the resin component can be melted. In such a situation, when the pressure in the case exceeds the open pressure and the pressure release valve is opened, the resin component melt may flow out of the pressure release valve. In this case, the melt may continue to flow down from the pressure release valve or may be scattered around the secondary battery. For example, when there are various devices around the secondary battery, it may be preferable that the cooled gas is released in one direction in order to suppress adverse effects on the various devices.

  An object of the present invention is made in view of the above-described circumstances, and is to provide a power storage device that can suitably cope with a case where pressure and temperature in a case become excessively high.

A power storage device that achieves the above object includes an electrode assembly in which electrodes are stacked via a separator, a case in which the electrode assembly is accommodated, a pressure in the case that is present in the case, and is determined in advance. A pressure release valve for releasing the pressure in the case when the open pressure is exceeded, and a position overlapping the pressure release valve when viewed from the opposing direction of the pressure release valve and the electrode assembly in the case characterized in that it comprises a first Fi emission extending in the opposite direction be one that is.

  According to this configuration, when the pressure in the case exceeds the open pressure, the gas generated in the case is released via the pressure release valve. In this case, it is assumed that the gas passes through the fins. Thereby, cooling of gas can be aimed at. Further, since the fin extends in the facing direction between the pressure release valve and the electrode assembly, the gas is rectified in the facing direction and released. Thereby, the cooled gas can be discharged in one direction.

  Furthermore, if the resin component or the like is melted due to excessively high temperature in the case, the melt is cooled and fixed by the fins. Thereby, even if it is a case where resin components etc. melt | dissolve, it can suppress that a melted material droops or scatters from a case. From the above, it is possible to cope with a case where the pressure and temperature in the case are excessively high.

For the electric storage device, may the be a viewed from the opposing direction that is disposed at a position overlapping with the pressure release valve in outside the casing and a second Fi emission extending in the opposite direction. According to such a configuration, since the power storage device includes both the first fin and the second fin, compared with the configuration including only one of the first fin and the second fin, Cooling and rectification can be performed more suitably, and the outflow of the melt can be more suitably suppressed.

  Regarding the power storage device, a plurality of the first fins and the second fins are arranged in a direction orthogonal to the facing direction, and the arrangement direction of the first fins and the arrangement direction of the second fins are: It is good to cross each other. According to such a configuration, since the arrangement direction of the first fins and the arrangement direction of the second fins intersect each other, the gas can be rectified so as to flow more preferably in the opposite direction.

  In the power storage device, a tab having a shape protruding from the end exists at the end of the electrode, and the power storage device includes a conductive member that connects the tab and a terminal present in the case, It is good to provide the 1st fin arrange | positioned in the position which overlaps with the said pressure release valve seeing from the said opposing direction in an electrically-conductive member. According to such a configuration, since the first fin is disposed at a position overlapping the pressure release valve as viewed from the opposing direction in the conductive member, the gas in the case passes through the first fin, and from the pressure release valve. Easy to be released. Thereby, cooling of gas etc. can be performed using a 1st fin, electrically connecting a tab and a terminal using a conductive member.

  In the power storage device, the second fin may have a recess that is recessed in a direction away from the pressure release valve. According to such a configuration, a gap is generated between the pressure release valve and the second fin. Thereby, when the pressure release valve is opened, the pressure release valve is unlikely to hit the second fin. Therefore, the disadvantage that the opening of the pressure release valve is hindered by the second fin can be suppressed.

  The power storage device may be a secondary battery.

  According to this invention, it can respond suitably when the pressure and temperature in the case become excessively high.

FIG. 2 is a perspective view showing a partially broken secondary battery according to the first embodiment. The exploded perspective view of an electrode assembly. The exploded perspective view of a secondary battery. The perspective view of a battery module. FIG. 5 is a sectional view taken along line 5-5 in FIG. FIG. 6 is a sectional view taken along line 6-6 in FIG. The disassembled perspective view of the secondary battery of 2nd Embodiment. The perspective view of the lid | cover of 2nd Embodiment. The bottom view of a lid.

(First embodiment)
Hereinafter, 1st Embodiment of an electrical storage apparatus is described using FIGS. In FIG. 5, for convenience of illustration, illustration of some components such as the positive electrode terminal 16, the positive electrode tab 31, and the positive electrode conductive member 40 is omitted, and the electrode assembly 14 is simplified.

  As shown in FIG. 1, a secondary battery 10 as a power storage device includes a rectangular parallelepiped case 11. The case 11 includes a bottomed box-shaped case main body 12 that is open on one side, and a rectangular flat lid 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 secondary battery 10 includes an electrode assembly 14 and an electrolyte solution 15 (see FIGS. 5 and 6) housed in a case 11, and a positive electrode terminal 16 and a negative electrode terminal 17 that exchange power with the electrode assembly 14. I have. Each terminal 16, 17 is on the lid 13 of the case 11 and is arranged in a state of penetrating the lid 13. The secondary battery 10 of the present embodiment is, for example, a lithium ion battery.

  As shown in FIG. 2, the electrode assembly 14 has a structure in which positive electrodes 21 and negative electrodes 22 are alternately stacked via separators 23, which are porous films through which ions related to electrical conduction can pass. Each of the electrodes 21 and 22 and the separator 23 is a rectangular sheet.

  The positive electrode 21 includes a rectangular positive metal foil (for example, an aluminum foil) 21a and positive electrode active material layers 21b on both surfaces of the positive metal foil 21a. The negative electrode 22 includes a rectangular negative metal foil (for example, copper foil) 22a and negative electrode active material layers 22b on both surfaces of the negative metal foil 22a. In the state constituting the electrode assembly 14, the positive electrode active material layer 21 b is covered with the negative electrode active material layer 22 b, and the electrodes 21 and 22 are covered with the separator 23.

  As shown in FIG. 2, the positive electrode 21 has a positive electrode tab 31 having a shape protruding from the end 21c. Similarly, the negative electrode 22 has a negative electrode tab 32 having a shape protruding from the end 22c. The negative electrode tab 32 is disposed at the center of the end portion 22 c of the negative electrode 22, and the positive electrode tab 31 is located at a position deviated from the center at the end portion 21 c of the positive electrode 21.

  The electrodes 21 and 22 are stacked so that the same polarities of the tabs 31 and 32 are arranged in a row. As shown in FIG. 3, the negative electrode tabs 32 are gathered together in one of the stacking directions Y of the electrodes 21, 22 and folded back to the other in the gathered state. Similarly, each positive electrode tab 31 is folded back to the other side in a state where the positive electrode tabs 31 are gathered toward one side in the stacking direction Y of the electrodes 21 and 22. The electrode assembly 14 is accommodated in the case 11 with the end surface 14a where the tabs 31 and 32 exist and the inner surface 13a of the lid 13 facing each other.

As shown in FIG. 3, the secondary battery 10 includes a positive electrode conductive member 40 and a negative electrode conductive member 50 that electrically connect the same polarities of the tabs 31 and 32 and the terminals 16 and 17.
The positive electrode conductive member 40 is between the lid 13 of the case 11 and the electrode assembly 14 and is joined (for example, welded) to both the positive electrode tabs 31 and the positive electrode terminals 16. As shown in FIG. 3, the positive electrode terminal 16 includes a positive electrode shaft portion 16a having a thread groove on the outer peripheral surface, and a prismatic positive electrode head portion 16b provided at an end portion in the axial direction of the positive electrode shaft portion 16a. Have. The positive electrode conductive member 40 has a crank shape as viewed from the stacking direction Y of the electrodes 21 and 22 by bending a single metal plate, for example, an aluminum plate, and is disposed relatively closer to the lid 13. A positive electrode part 41 and a second positive electrode part 42 disposed closer to the electrode assembly 14 than the first positive electrode part 41 are included. In the positive electrode conductive member 40, the first positive electrode part 41 is bonded to each positive electrode tab 31, and the second positive electrode part 42 is bonded to the positive electrode head portion 16b, so that the positive electrode tab 31 and the positive electrode terminal 16 are electrically connected. doing.

  Similar to the positive electrode side, the negative electrode terminal 17 has a negative electrode shaft portion 17a and a negative electrode head portion 17b. The negative electrode conductive member 50 is between the lid 13 of the case 11 and the electrode assembly 14. The negative electrode conductive member 50 has a crank shape as viewed from the stacking direction Y of the electrodes 21 and 22 by bending a single metal plate, for example, a copper plate, and is a first negative electrode disposed relatively near the lid 13. It has a part 51 and a second negative electrode part 52 disposed closer to the electrode assembly 14 than the first negative electrode part 51. Each of the negative electrode parts 51 and 52 has a plate shape extending in the stacking direction Y of the electrodes 21 and 22 and the width direction X of the electrode assembly 14. The width direction X of the electrode assembly 14 is a direction orthogonal to both the facing direction Z between the inner surface 13 a of the lid 13 and the end surface 14 a of the electrode assembly 14 and the stacking direction Y of the electrodes 21 and 22.

  Here, as already described, the negative electrode tab 32 is disposed at the center of the end 22c of the negative electrode 22, while the positive electrode tab 31 is disposed at a position deviated from the center at the end 21c of the positive electrode 21. Yes. For this reason, as shown in FIG. 3, in the width direction X of the electrode assembly 14, the distance between the negative electrode tab 32 and the negative electrode terminal 17 is longer than the distance between the positive electrode tab 31 and the positive electrode terminal 16. Correspondingly, the length of the first negative electrode part 51 in the width direction X of the electrode assembly 14 is longer than the corresponding length of the first positive electrode part 41. The first negative electrode part 51 and each negative electrode tab 32 overlap each other when viewed from the facing direction Z. In the negative electrode conductive member 50, the first negative electrode part 51 is bonded to the negative electrode tab 32, and the second negative electrode part 52 is bonded to the negative electrode head portion 17b, whereby the negative electrode tab 32 and the negative electrode terminal 17 are electrically connected. Connected.

  Incidentally, as shown in FIG. 3, the ends of the terminals 16 and 17 opposite to the heads 16b and 17b in the shaft portions 16a and 17a pass through the through holes 13b existing in the lid 13 and are outside the case 11. A nut 62 is screwed into the protruding portion with the insulating ring 61 inserted therethrough.

  An O-ring 63 as a seal member is attached to the shaft portions 16a and 17a of the terminals 16 and 17, respectively. By compressing the O-ring 63 between the heads 16b and 17b and the lid 13, the periphery of the shafts 16a and 17a is sealed.

  The secondary battery 10 includes a positive electrode side insulating member 64 that covers the positive electrode head portion 16 b of the positive electrode terminal 16 and the second positive electrode part 42. The positive electrode side insulating member 64 is fitted to the positive electrode head portion 16b and the positive electrode shaft portion 16a in a state in which the surface of the second positive electrode part 42 facing the end surface 14a of the electrode assembly 14 is covered. Similarly, in the secondary battery 10, the negative electrode side insulating member 65 fitted to the negative electrode head portion 17 b and the negative electrode shaft portion 17 a while covering the surface of the second negative electrode part 52 that faces the end surface 14 a of the electrode assembly 14. It has.

  As shown in FIG. 3, the secondary battery 10 includes an insulating sheet 66 that insulates the electrode assembly 14 from the case 11. The insulating sheet 66 has, for example, a box shape that is opened in one direction by bending a single rectangular resin sheet. The electrode assembly 14 is accommodated in a box-shaped insulating sheet 66.

  As shown in FIG. 4, the plurality of secondary batteries 10 are assembled in a state where the surfaces orthogonal to the stacking direction Y of the electrodes 21 and 22 in the case 11 are opposed to each other by, for example, a resin assembly frame F. The battery module M is configured.

  As shown in FIGS. 5 and 6, the case 11, specifically the lid 13, has a pressure release valve 70 for releasing the pressure in the case 11 when the pressure in the case 11 exceeds a predetermined release pressure. There is. The pressure release valve 70 is a valve that opens when the pressure in the case 11 exceeds the release pressure, and has a thin plate-like valve body 71 that is thinner than the thickness of the lid 13. The valve body 71 has a flat shape when viewed from the facing direction Z. Further, a groove 72 is present on the outer surface 71 a of the valve body 71 exposed outside the case 11.

  According to such a configuration, when gas is generated in the case 11 due to the electrode assembly 14 generating excessive heat for some reason, the pressure in the case 11 becomes high. And when the pressure in case 11 exceeds an open pressure, the part in which the groove | channel 72 in the valve body 71 exists cleaves. Thereby, the gas in the case 11 is released through the pressure release valve 70.

  The opening pressure is defined by the thinness of the valve body 71, the depth of the groove 72, and the like. The thinness of the valve body 71 and the depth of the groove 72 are determined by the case 11 itself, the case body 12 and the lid. The pressure relief valve 70 is set to be opened before cracks or breaks occur at the joint with the joint 13.

Incidentally, the facing direction Z between the inner surface 13a of the lid 13 and the end surface 14a of the electrode assembly 14 can be said to be the facing direction of the pressure release valve 70 and the electrode assembly 14 or the thickness direction of the valve body 71.
Here, when a high-temperature gas is generated in the case 11, some components housed in the case 11 may melt. Specifically, for example, the separator 23, the insulating sheet 66, and the insulating members 64 and 65 are made of a resin material such as polyethylene or polypropylene. Such a resin material may be melted by a high-temperature gas (for example, 200 ° C. or more) generated in the case 11. Such a melt may flow out of the pressure release valve 70 and adversely affect various devices existing around the secondary battery 10.

  Further, in the battery module M in which the plurality of secondary batteries 10 are assembled using the resin assembling frame F, the high-temperature gas is diffused and discharged in the direction intersecting the facing direction Z via the pressure release valve 70. If it does, there exists a possibility of having a bad influence with respect to the various apparatuses which exist around the secondary battery 10 by which the pressure release valve 70 was open | released, for example, the adjacent secondary battery 10 and the assembly | attachment frame F. FIG. For this reason, it is desirable that as low a temperature gas as possible be released in the facing direction Z.

  On the other hand, the secondary battery 10 of this embodiment includes a first fin 81 and a second fin 82 that rectify and cool the gas in the case 11. The fins 81 and 82 will be described in detail below.

  In the following description, for convenience of explanation, the direction approaching the electrode assembly 14 from the pressure release valve 70 is simply referred to as “downward”, and the direction away from the pressure release valve 70 to the electrode assembly 14 is simply referred to as “upward”. In this case, it can be said that the facing direction Z is also the vertical direction.

  First, the first fin 81 will be described. As shown in FIGS. 5 and 6, the first fin 81 is disposed at a position overlapping the pressure release valve 70 when viewed from the facing direction Z in the case 11. Specifically, the pressure release valve 70 is present at a substantially central portion in the longitudinal direction of the lid 13, and the pressure release valve 70, the first negative electrode part 51 of the negative electrode conductive member 50, and the negative electrode in order from the upper side to the lower side. A tab 32 is arranged. A plurality of first fins 81 are present at positions overlapping with the pressure release valve 70 when viewed from above on the upper surface 51a that is a surface facing the pressure release valve 70 in the first negative electrode part 51.

  As shown in FIGS. 5 and 6, the plurality of first fins 81 stand in the facing direction Z from the upper surface 51 a of the first negative electrode part 51. Each first fin 81 has a plate shape extending in the facing direction Z and the width direction X of the electrode assembly 14. The first fins 81 are arranged side by side in the stacking direction Y of the electrodes 21 and 22.

  The first fin 81 is made of the same material as the negative electrode conductive member 50, for example, copper, and is integrally formed with the negative electrode conductive member 50. Although the specific method of integrally forming the first fin 81 and the negative electrode conductive member 50 is arbitrary, for example, welding or forging may be used. In the configuration in which the first fin 81 is welded to the negative electrode conductive member 50, the first negative electrode part 51 and the negative electrode tab 32 may be welded first, and then the first fin 81 may be welded to the first negative electrode part 51. .

  As shown in FIG. 5, among the first fins 81, the distance Y1 between the ends of the electrodes 21 and 22 in the stacking direction Y is the same as that in the stacking direction Y of the electrodes 21 and 22 of the pressure release valve 70. It is set longer than the maximum length Y0. And as shown in FIG. 6, the length X1 of the width direction X of each 1st fin 81 of this embodiment is set longer than the maximum length X0 of the width direction X of the pressure release valve 70. As shown in FIG. That is, the first fin 81 exists over the entire region overlapping the pressure release valve 70 as viewed from above on the upper surface 51 a of the first negative electrode part 51. The length X1 is longer than the length of the first negative electrode part 51 in the short direction (the stacking direction Y of the electrodes 21 and 22).

  Next, the second fin 82 will be described. As shown in FIGS. 5 and 6, the second fin 82 is disposed at a position overlapping the pressure release valve 70 when viewed from the opposite direction Z outside the case 11, specifically, above the pressure release valve 70. The second fins 82 have a plate shape extending in the facing direction Z and the stacking direction Y of the electrodes 21 and 22, and a plurality of the second fins 82 are arranged side by side in the width direction X of the electrode assembly 14. In this case, the arrangement direction of the first fins 81 and the arrangement direction of the second fins 82 intersect (specifically, orthogonal).

  As shown in FIG. 5, the second fin 82 has a recess 83 that is recessed in a direction away from the pressure release valve 70, specifically, upward. In this case, when viewed from the width direction X of the electrode assembly 14, which is the arrangement direction of the second fins 82, the second fins 82 have an inverted U shape that is convex upward. A gap S exists between the pressure release valve 70 and the second fin 82. The second fin 82 is made of the same material as the lid 13, for example. The second fin 82 is integrally formed with the lid 13 by being welded to the outer surface of the lid 13.

  As shown in FIG. 3, the secondary battery 10 includes an insulating cover 90 that restricts contact between the conductive members 40 and 50 and the case 11. The insulating cover 90 is disposed between the conductive members 40 and 50 and the case 11 (specifically, the lid 13). The insulating cover 90 includes a rectangular plate-shaped main body portion 91 and standing portions 92 that stand downward from the four corners of the opposing surfaces (lower surfaces) of the main body portion 91 facing the conductive members 40 and 50. As shown in FIGS. 5 and 6, the standing dimension Z <b> 1 of the standing part 92 is set longer than the standing dimension Z <b> 2 from the upper surface 51 a of the first negative electrode part 51 of the first fin 81. The insulating cover 90 is disposed across the conductive members 40 and 50 in a state where the leading end of the upright portion 92 is in contact with the first positive electrode part 41 and the first negative electrode part 51. In addition, the contact part of the front-end | tip part of the standing part 92 and the 1st positive electrode part 41 or the 1st negative electrode part 51 is joined by welding, adhesion | attachment, etc.

  Further, a through hole 93 exists at a position overlapping the pressure release valve 70 when viewed from the opposing direction Z in the insulating cover 90, specifically at a position below the pressure release valve 70 in the insulating cover 90. The through hole 93 has the same shape as the outer shape of the pressure release valve 70, specifically the valve body 71. The through-hole 93 communicates with the pressure release valve 70 so that the gas flow toward the pressure release valve 70 via the first fin 81 is not hindered.

Next, the operation of this embodiment will be described.
As shown by a two-dot chain line in FIG. 6, when gas is generated in the case 11, the gas is released through the first fin 81 → the through hole 93 → the pressure release valve 70 → the second fin 82. . In this case, the gas is cooled by the fins 81 and 82 and rectified in the facing direction Z.

  When the resin component is melted, the melt is cooled by the first fins 81 and fixed by the first fins 81. This makes it difficult for the melt to flow out of the case 11. Furthermore, if the melt flows out from the pressure release valve 70, the melt is fixed by the second fin 82. Therefore, since the melt of the resin component is trapped by the first fin 81 or the second fin 82, the melt is unlikely to continue to drip from the pressure release valve 70 or to be scattered.

According to the embodiment described on more than the following effects.
(1) The secondary battery 10 is disposed at a position overlapping the pressure release valve 70 when viewed from the facing direction Z between the pressure release valve 70 and the electrode assembly 14 in the case 11 and extends in the facing direction Z. The first fin 81 and the second fin 82 that is disposed at a position overlapping the pressure release valve 70 when viewed from the facing direction Z outside the case 11 and extends in the facing direction Z are provided. Thereby, when the electrode assembly 14 generates heat excessively and high temperature gas is generated in the case 11, the high temperature gas is cooled and discharged in a state of being rectified in the facing direction Z. be able to. Therefore, various devices existing around the secondary battery 10 with the pressure release valve 70 opened, for example, another secondary battery 10 adjacent to the secondary battery 10 in the stacking direction Y of the electrodes 21 and 22. In addition, it is possible to suppress adverse effects that may be caused by high-temperature gas striking the assembly frame F or the like for assembling a plurality of secondary batteries 10.

  In addition, when the resin component or the like in the case 11 is melted due to the heat generation of the electrode assembly 14 or the like, the melt can be trapped by the fins 81 and 82, so that the melt flows down from the case. It can be suppressed that it becomes or scatters.

  Further, if there is a relatively large foreign material, for example, a foreign material having a particle diameter equal to or larger than the fin pitch of the fins 81 and 82 in the case 11, the foreign material is caught by the fins 81 and 82. Thereby, discharge | release etc. of the said foreign material can be suppressed.

  (2) In particular, the secondary battery 10 includes both the first fin 81 and the second fin 82. Therefore, compared with the configuration provided with only one of the fins 81 and 82, the gas can be cooled and rectified more preferably, and the outflow of the melt can be suitably suppressed.

  (3) A plurality of first fins 81 and second fins 82 are arranged in a direction orthogonal to the facing direction Z, and the arrangement direction of the first fins 81 and the arrangement direction of the second fins 82 intersect each other. doing. Specifically, a plurality of first fins 81 are arranged in the stacking direction Y of the electrodes 21, 22, and a plurality of second fins 82 are arranged in a row in the width direction X of the electrode assembly 14. Thereby, the gas in the case 11 can be rectified in the facing direction Z more preferably.

  (4) The second fin 82 has a recess 83 that is recessed upward, which is the direction away from the pressure release valve 70. As a result, a gap S is generated between the pressure release valve 70 and the second fin 82. Therefore, when the pressure release valve 70 is opened, the valve body 71 is unlikely to hit the second fin 82. Therefore, the inconvenience that the opening of the pressure release valve 70 is hindered by the second fin 82 can be suppressed.

  (5) The electrode assembly 14 is configured by laminating the electrodes 21 and 22 and the separator 23, and the end portions 21c and 22c of the electrodes 21 and 22 have a shape protruding from the end portions 21c and 22c. The tabs 31 and 32 exist, and the secondary battery 10 includes conductive members 40 and 50 that connect the terminals 16 and 17 and the tabs 31 and 32. In such a configuration, a part of the negative electrode conductive member 50 of each of the conductive members 40 and 50 is disposed at a position overlapping the pressure release valve 70 when viewed from the facing direction Z, and the first fin 81 has the negative electrode conductive member 50. Are disposed at the overlapping positions. Specifically, the negative electrode conductive member 50 includes a first negative electrode part 51 welded to the negative electrode tab 32. And the 1st fin 81 exists in the position which overlaps with the pressure release valve 70 seeing from the opposing direction Z among the upper surfaces 51a of the 1st negative electrode part 51. As shown in FIG. As a result, gas cooling or the like can be performed using the first fins 81 while the negative electrode tab 32 and the negative electrode terminal 17 are electrically connected.

  (6) The first fin 81 is thermally coupled to the negative electrode conductive member 50. Specifically, the first fin 81 is made of copper of the same material as the negative electrode conductive member 50 and is integrally formed with the negative electrode conductive member 50. Thereby, since the heat of the first fin 81 is transmitted to the negative electrode conductive member 50, the cooling performance of the first fin 81 can be improved.

  In particular, the first fin 81 is attached to the negative electrode conductive member 50, and the second fin 82 is attached to the lid 13. Thereby, the heat absorbed by the fins 81 and 82 can be diffused as compared with the configuration in which the fins 81 and 82 are attached to one member.

  (7) The first negative electrode part 51 extends in the width direction X of the electrode assembly 14, and correspondingly, the first fin 81 extends in the facing direction Z and the width direction X of the electrode assembly 14. ing. That is, the first fin 81 is arranged so that the longitudinal direction thereof coincides with the longitudinal direction of the first negative electrode part 51. Thereby, since the dimension of the longitudinal direction of the 1st fin 81 can fully be ensured, the further improvement of the cooling performance etc. of the 1st fin 81 can be aimed at.

  More specifically, in the configuration in which the first fin 81 is erected on the upper surface 51 a of the first negative electrode part 51, the first fin 81 is viewed from above from the viewpoint of suppressing contact between the first fin 81 and the case 11. It is preferable that the fin 81 does not protrude from the first negative electrode part 51. In this case, if the first fin 81 is provided so as to extend in the short direction of the first negative electrode part 51, that is, in the stacking direction Y of the electrodes 21 and 22, the dimension in the longitudinal direction of the first fin 81 is It is necessary to make the dimension of the first negative electrode part 51 shorter than the short dimension.

  On the other hand, in the present embodiment, the longitudinal direction of the first fin 81 and the longitudinal direction of the first negative electrode part 51 coincide. Thereby, compared with the structure with which the longitudinal direction of the 1st fin 81 and the transversal direction of the 1st negative electrode part 51 correspond, the dimension of the longitudinal direction of the 1st fin 81 can be ensured long. Therefore, the contact area with the gas can be improved, and the cooling performance and the like of the first fin 81 can be further improved.

  Further, since the longitudinal direction of the first fin 81 and the longitudinal direction of the first negative electrode part 51 coincide, when the first fin 81 and the negative electrode conductive member 50 are formed by forging, the forging is comparatively performed. It can be done easily.

  (8) The secondary battery 10 includes an insulating cover 90 that restricts contact between the conductive members 40 and 50 and the case 11. The insulating cover 90 is disposed between the conductive members 40 and 50 and the lid 13 so as not to interfere with the first fins 81. Specifically, the insulating cover 90 includes a plate-like main body portion 91, and an upright portion 92 that stands up from the surface of the main body portion 91 that faces the conductive members 40 and 50 and that is longer than the standing dimension Z <b> 2 of the first fin 81. The upright portion 92 is arranged in contact with the conductive members 40 and 50. Thereby, in the structure which has the 1st fin 81 in the negative electrode conductive member 50, each conductive member 40 and 50 and the case 11 can be insulated suitably.

(Second Embodiment)
In the present embodiment, the position and the like of the negative electrode tab 32 are different. The different points will be described with reference to FIGS. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 7, in the present embodiment, the negative electrode tab 32 is disposed on the opposite side of the positive electrode tab 31 from the position overlapping the pressure release valve 70 as viewed from above. Correspondingly, the length of the first negative electrode part 101 of the negative electrode conductive member 100 in the width direction X is shorter than that of the first negative electrode part 51 of the first embodiment. In this case, the negative electrode conductive member 100 and the negative electrode tab 32 do not exist in the space between the pressure release valve 70 and the electrode assembly 14.

  As shown in FIGS. 8 and 9, the first fin 111 of the present embodiment is disposed at a position below the pressure release valve 70 and is attached to the inner surface 13 a of the lid 13. As in the first embodiment, the first fin 111 has a rectangular plate shape extending in the facing direction Z and the width direction X of the electrode assembly 14, and there are a plurality of first fins 111 aligned in the stacking direction Y of the electrodes 21 and 22. The first fin 111 of the present embodiment is made of the same material as the lid 13 and is integrally formed with the lid 13.

  As shown in FIG. 7, the insulating cover 112 of the present embodiment has a rectangular plate shape without the upstanding portion 92. The insulating cover 112 is disposed across the first negative electrode part 51 and the first positive electrode part 41, and is interposed between the first negative electrode part 51 and the first positive electrode part 41 and the inner surface 13 a of the lid 13. .

According to the embodiment described above in detail, the following operational effects are obtained.
(9) The first fin 111 disposed in the case 11 and at a position below the pressure release valve 70 is attached to the case 11, specifically the lid 13. Thereby, there exists an effect of (1)-(4).

  (10) In particular, since both the first fin 111 and the second fin 82 are attached to the lid 13 where the pressure release valve 70 exists, misalignment or the like hardly occurs between these three members. Thereby, the fall of the cooling performance etc. resulting from the position shift between the said 3 persons can be suppressed.

  (11) The first fin 111 is integrally formed with the lid 13. Thereby, the heat absorbed by the first fins 111 is transmitted to the lid 13. Therefore, the gas can be suitably cooled using the first fins 111.

In addition, you may change each said embodiment as follows.
One of the first fins 81 and 111 and the second fins 82 may be omitted. In short, the secondary battery 10 may include at least one of the first fins 81 and 111 and the second fins 82.

  The number of the first fins 81 and the number of the second fins 82 are arbitrary, and may be one or plural. Further, the number of first fins 81 and the number of second fins 82 may be the same or different.

  (Circle) the position of the pressure release valve 70 is not restricted to the center part of the lid | cover 13, and is arbitrary. For example, the pressure release valve 70 may be disposed closer to the negative electrode terminal 17 than the central portion of the lid 13. In this case, the position of the first fin 81 may be adjusted so that the first fin 81 is disposed below the pressure release valve 70.

  The pressure release valve 70 may exist on a predetermined wall portion of the case body 12 instead of the lid 13. In this case, the electrode assembly 14 may be accommodated in the case 11 so that the wall portion where the pressure release valve 70 exists and the end surface 14a of the electrode assembly 14 face each other.

  The arrangement direction of the first fins 81 and 111 and the arrangement direction of the second fins 82 are orthogonal to each other. However, the arrangement is not limited to this. In addition, the arrangement direction of the first fins 81 and 111 may coincide with the arrangement direction of the second fins 82.

The longitudinal direction of the first fin 81 and the longitudinal direction of the first negative electrode part 51 may intersect or be orthogonal to each other.
The positive electrode tab 31 may be disposed at the center of the end 21c of the positive electrode 21, and the first positive electrode part 41 may be extended to a position below the pressure release valve 70 correspondingly. . In this case, the first fin 81 may be erected on the surface of the first positive electrode part 41 that faces the pressure release valve 70. In such a configuration, the negative electrode tab 32 is preferably located at a position deviated from the central portion of the end 22 c of the negative electrode 22.

  Each conductive member 40, 50 has a curved crank shape when viewed from the stacking direction Y of the electrodes 21, 22, but is not limited thereto, and is linear when viewed from the stacking direction Y of the electrodes 21, 22. Also good.

○ The recess 83 of the second fin 82 may be omitted.
The specific configuration and shape of the pressure release valve 70 are arbitrary. For example, the structure which attaches the valve which forms a through-hole in the lid | cover 13 and plugs up the said through-hole may be sufficient.

The first fin 81 is made of the same material as the negative electrode conductive member 50, but is not limited thereto, and may be made of a different material. The same applies to the second fins 82.
The first fin 81 is in the entire region located below the pressure release valve 70 in the upper surface 51a of the first negative electrode part 51, but is not limited thereto, and may be in a part of the region. For example, one or a plurality of first fins may be provided in a part of the region, and the negative electrode tab 32 and the first negative electrode part 51 may be welded in other regions.

The electrode assembly 14 may be a wound type in which a strip-shaped positive electrode and a negative electrode are wound through a strip-shaped separator to form a laminated structure.
The secondary battery 10 may be mounted on a vehicle and used for traveling, or may be used as a stationary power source.

○ The shape of the case 11 is arbitrary, and may be, for example, a cylindrical shape.
The secondary battery 10 is a lithium ion battery, but is not limited thereto, and may be another secondary battery. In short, any ion may be used as long as ions move between the positive electrode active material layer 21b and the negative electrode active material layer 22b and transfer charges. Further, an electric double layer capacitor may be used as the power storage device.

Next, a preferable example that can be grasped from the embodiment and another example will be described below.
(A) An electrode assembly in which electrodes are stacked via a separator, a case in which the electrode assembly is accommodated, and a pressure in the case that exceeds a predetermined open pressure A pressure release valve for releasing the pressure in the case in the case, a tab having a shape protruding from the end exists at the end of the electrode, the power storage device And a conductive member that connects the terminals present in the case, and a fin provided in the conductive member.

  According to this configuration, part of the gas generated in the case can pass through the fins and be released from the pressure release valve. Thereby, cooling of the gas discharge | released from a pressure release valve can be aimed at. When paying attention to the above configuration, the first fins 81 may be arranged not at a position below the pressure release valve 70 but at a position shifted from the position below. For example, the first fin on the surface (upper surface) facing the inner surface 13a of the lid 13 in the first negative electrode part 101 of the second embodiment or the surface (upper surface) facing the inner surface 13a of the lid 13 in the first positive electrode part 41. There may be 81.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 11 ... Case, 13 ... Cover, 14 ... Electrode assembly, 16, 17 ... Terminal, 21, 22 ... Electrode, 23 ... Separator, 31, 32 ... Tab, 40, 50, 100 ... Conductive member , 70: Pressure release valve, 81, 111: First fin, 82: Second fin, 83: Recess.

Claims (6)

An electrode assembly in which electrodes are stacked via a separator;
A case in which the electrode assembly is accommodated;
A pressure release valve that is present in the case and that releases the pressure in the case when the pressure in the case exceeds a predetermined opening pressure;
That it comprises a first Fi emission extending in the opposite direction be one that is disposed at a position overlapping with the pressure release valve when viewed from the opposing direction of said pressure release valve and the electrode assembly within the case A power storage device characterized by the above. The power storage device according to claim 1, further comprising a second Fi emission extending in the opposite direction be one that is disposed at a position overlapping with the pressure release valve when viewed from the opposing direction of the outside the case. A plurality of the first fins and the second fins are arranged in a direction orthogonal to the facing direction,
The power storage device according to claim 2, wherein the arrangement direction of the first fins and the arrangement direction of the second fins intersect each other. At the end of the electrode, there is a tab having a shape protruding from the end,
The power storage device
A conductive member that connects the tab and a terminal present in the case;
The first fin disposed at a position overlapping the pressure release valve as viewed from the facing direction of the conductive member;
The electrical storage apparatus as described in any one of Claims 1-3 provided with these. The power storage device according to any one of claims 2 to 4, wherein the second fin includes a recess that is recessed in a direction away from the pressure release valve.   The power storage device according to any one of claims 1 to 5, wherein the power storage device is a secondary battery.