JP6690578B2 - Power storage device - Google Patents

Description

  The present disclosure relates to a power storage device.

  Conventionally, various types of power storage devices such as secondary batteries have been proposed. The secondary battery includes an electrode body, an electrolytic solution, a housing case, an electrode terminal, and a collector terminal. The electrode body, the electrolytic solution, and the collector terminal are housed in a housing case. The collector terminal is connected to the positive electrode or the negative electrode of the electrode body. The electrode terminal is provided on the upper surface of the housing case.

  As described in Japanese Patent Application Laid-Open No. 2008-066254 and the like, a current interrupt device (CID: Current Interrupt Device) may be mounted on a secondary battery as a measure against overcharge. The current interrupting device is a device that disconnects electrical connection between the electrode terminal and the current collecting terminal when the internal pressure in the housing case rises due to overcharging or the like.

  For example, the current interruption device described in Japanese Patent Laid-Open No. 2013-161712 is formed by a reversing plate and a current collecting terminal.

  The collector terminal includes a main body and legs. The main body is arranged along the lower surface of the housing case. The leg portion is connected to an end portion of the main body portion and is arranged so as to extend downward from the main body portion. The main body portion includes a leg support portion to which the leg portions are connected, and a thin wall portion formed thinner than the leg support portion. A hole is formed in the thin portion, and the reversal plate closes the hole and is joined to the thin portion. An engraved portion is formed in a portion of the thin-walled portion that is located around the joint with the reversal plate.

  In this current interrupting device, when the internal pressure in the housing case rises due to overcharging or the like, the reversing portion receives the pressure in the housing case through the hole. When the pressure applied to the reversal plate increases, the engraved portion breaks, and further, the broken portion progresses, so that the thin portion breaks.

  When the thin portion is broken, the reversal plate is inverted and deformed upward, and the reversal plate and the current collector terminal are electrically disconnected.

  The current interruption device described in JP-A-2014-035831 includes a reversing plate, a protrusion provided above the reversing plate, and a connection terminal arranged on the protrusion. The connection terminal has a hollow portion communicating with the outside of the housing case. A through hole communicating with the hollow portion of the connection terminal is formed in the protrusion.

  When the internal pressure in the housing case rises and the reversal plate is inverted and deformed, the protrusion penetrates the reversal plate. When the protrusion penetrates the reversal plate, the inside of the housing case and the outside of the housing case communicate with each other through the through hole and the hollow portion. Then, the quenching treatment can be performed by introducing the quenching agent from the opening of the hollow portion of the terminal portion.

JP, 2008-066254, A JP, 2014-035831, A JP, 2013-161712, A

  In the secondary battery provided with the current interruption device described in JP 2013-161712 A, when the internal pressure in the housing case rises, the electrical connection between the electrode terminal and the current collecting terminal is cut off. Therefore, the electric energy in the housing case cannot be released from the electrode terminal to the outside, and the deactivation process cannot be applied to the electrode body.

  In the current interrupting device described in Japanese Patent Laid-Open No. 2014-035831, there is a case where the protrusion cannot penetrate the reversal plate when the reversal plate is inverted and deformed. As a result, the deactivator may not be supplied into the housing case.

  The present disclosure has been made in view of the above problems, and its purpose is to provide an electrical connection between the electrode terminal and the current collecting terminal when the internal pressure in the housing case becomes equal to or higher than a predetermined value. An object of the present invention is to provide a power storage device that can disconnect the connection and can favorably supply the deactivator into the housing case.

  A power storage device according to the present disclosure includes a power storage element, a housing case that houses the power storage element, a current collector terminal that is provided in the housing case, is connected to the power storage element, and is provided on an outer surface of the housing case. An electrode terminal electrically connected to the terminal and a current interruption device provided in an electrical connection path between the current collecting terminal and the electrode terminal are provided.

  The current collector terminal has a through hole that opens inside the housing case. The current cutoff device is housed in the housing space, a reversal plate that covers the through hole from the outside of the housing case, a cover member that covers the reversal plate from the outside of the housing case, and forms a housing space between the reversal plate and the housing space. And a deactivator.

  The reversal plate is formed such that the thickness of the reversal plate is thin, and a notch portion that is broken when the internal pressure in the housing case rises is formed. The notch is formed at a position where, when the notch breaks, the deactivator leaking from the broken portion of the notch can flow into the housing case.

  According to the above power storage device, when the internal pressure in the housing case rises, pressure is applied to the reversal plate through the through hole, and tensile force is applied to the cutout portion. When the internal pressure in the housing case reaches or exceeds a predetermined value, the cutout portion breaks. Then, as the rupture portion progresses, the reversal plate separates from the collector electrode, and the electrical connection between the collector electrode and the electrode terminal is disconnected.

  When the cutout portion is broken, the deactivator in the accommodation space leaks out, enters the accommodation case through the through hole formed in the current collector terminal, and deactivates the electrode body.

  According to the power storage device of the present disclosure, when the internal pressure in the housing case becomes equal to or higher than a predetermined value, it is possible to disconnect the electrical connection between the electrode terminal and the current collecting terminal, and to remove the deactivator. It can be satisfactorily supplied into the storage case.

FIG. 3 is a perspective view showing power storage device 1 according to the present embodiment. It is sectional drawing in the II-II line shown in FIG. It is a cross-sectional perspective view showing an external terminal 5. FIG. 6 is a cross-sectional view showing a configuration of a bottom plate 50 of the reversing plate 30 and its periphery. It is sectional drawing which shows the state which the electric current interruption apparatus 27 driven. 9 is a cross-sectional view showing a current interrupting device 27 according to Comparative Example 2. FIG. FIG. 7 is a cross-sectional view showing a state when the current cutoff device 27A operates in a power storage device including the current cutoff device 27A shown in FIG. 6.

  The power storage device according to the present embodiment will be described with reference to FIGS. 1 to 7. Of the configurations shown in FIGS. 1 to 7, the same or substantially the same configurations are denoted by the same reference numerals, and duplicated description will be omitted.

  FIG. 1 is a perspective view showing power storage device 1 according to the present embodiment. The power storage device 1 includes an electrode body 2, a housing case 3, an external terminal 4, an external terminal 5, a current collecting terminal 6, and a current collecting terminal 7. The electrode body 2 is formed by stacking a sheet-shaped positive electrode plate, a sheet-shaped separator, and a sheet-shaped negative electrode plate, and then winding them. The electrode body 2 is formed in a flat shape. The positive electrode is located at one end of the electrode body 2, and the negative electrode is located at the other end of the electrode body 2. The positive electrode is formed by an uncoated portion of the positive electrode plate which is not coated with the positive electrode active material. The negative electrode is formed by an uncoated portion of the negative electrode plate on which the negative electrode active material or the like is not coated.

  The housing case 3 includes a top wall 10, a bottom wall 11, main walls 12 and 13, and end side walls 14 and 15. The main walls 12 and 13 are arranged in the thickness direction of the housing case 3, and the end sidewalls 14 and 15 are arranged in the width direction of the housing case 3.

  The external terminals 4 and 5 are arranged on the upper surface of the upper wall 10 with a space therebetween. The external terminal 4 includes an electrode terminal 20, a metal plate 21, and a current interruption device 22.

  The electrode terminal 20 is formed so as to project upward from the upper surface of the upper wall 10. The metal plate 21 is formed so as to connect the current interrupt device 22 and the electrode terminal 20.

  The external terminal 5 includes an electrode terminal 25, a metal plate 26, and a current interruption device 27. The electrode terminal 25 is formed so as to project upward from the upper surface of the upper wall 10. The metal plate 26 is formed so as to connect the electrode terminal 25 and the current interruption device 27.

  The collector terminal 6 electrically connects the negative electrode of the electrode body 2 and the external terminal 4. The collector terminal 7 electrically connects the positive electrode of the electrode body 2 and the external terminal 5.

  2 is a sectional view taken along line II-II shown in FIG. 1, and FIG. 3 is a sectional perspective view showing the external terminal 5. The external terminal 5 includes a reversal plate 30, a metal cover 31, a connection terminal 32, a metal plate 33 of the collector terminal 7, an insulating member 34, a deactivator 36, an insulating member 38, and an insulating member 39. including.

  The collector terminal 7 includes a metal plate 33 and legs 37. The metal plate 33 is arranged on the lower surface side of the upper wall 10 of the electrode body 2 and extends along the upper wall 10. The leg portion 37 is connected to the end portion of the metal plate 33 and extends downward. The lower end of the metal plate 33 is connected to the negative electrode of the electrode body 2.

  Through holes 40, through holes 41, and through holes 42 are formed in the metal plate 33 at intervals.

  The insulating member 34 includes a vertical wall 34A, a lower plate 34B, an upper plate 34C, and an engaging portion 34D. The lower plate 34B is arranged on the lower surface of the metal plate 33. The lower plate 34B is arranged so as not to block the through holes 40, 41, 42 formed in the metal plate 33.

  The upper plate 34C is arranged on the upper surface of the metal plate 33. A through hole 43, a through hole 44, and a through hole 45 are formed in the upper plate 34C.

  The through hole 40 of the metal plate 33 and the through hole 43 of the upper plate 34C communicate with each other. The through hole 41 of the metal plate 33 and the through hole 44 of the upper plate 34C communicate with each other. The through hole 42 of the metal plate 33 and the through hole 45 of the upper plate 34C communicate with each other.

  The reversal plate 30 includes a bottom plate 50, a peripheral wall portion 51, and a main wall portion 52. The bottom plate 50 is arranged on the upper surface of the metal plate 33, and the bottom plate 50 is joined to the metal plate 33 by welding or the like.

  The peripheral wall portion 51 is formed so as to rise upward from the outer peripheral edge portion of the bottom plate 50. The peripheral wall portion 51 is connected to the upper end portion of the bottom plate 50. A recess is formed on the upper surface of the reversal plate 30 by the bottom plate 50, the peripheral wall portion 51, and the main wall portion 52. The bottom plate 50 is arranged so as to close the opening of the through hole 41. The main wall portion 52 is arranged so as to close the through hole 43 and the through hole 45.

  The metal cover 31 is arranged on the outer side of the housing case 3 with respect to the reversing plate 30, and is arranged so as to cover the reversing plate 30.

  The metal cover 31 includes a holding portion 46, a peripheral wall portion 47, and a top plate portion 48. The sandwiching portion 46 is arranged on the outer peripheral edge portion of the reversing plate 30, and the outer peripheral edge portion of the reversing plate 30 is sandwiched by the sandwiching portion 46 and the insulating member 34. The holding portion 46 is formed in an annular shape, and the peripheral wall portion 47 is formed so as to extend upward from the inner peripheral edge portion of the holding portion 46. The top plate portion 48 is formed at the upper end of the top plate portion 48. An accommodation space 35 is formed between the metal cover 31 and the reversal plate 30.

  The connection terminal 32 is fitted in a hole formed in the top plate portion 48 of the metal cover 31. The metal plate 26 is electrically connected to the connection terminal 32, and the connection terminal 32 and the electrode terminal 25 shown in FIG. 1 are electrically connected.

  The quenching agent 36 is housed in the housing space 35. The quenching agent 36 is, for example, salt water. The internal pressure in the accommodation space 35 is, for example, about 1 Pa. The internal pressure of the accommodation space 35 is lower than the internal pressure of the accommodation case 3 during overcharge. The insulating member 38 is arranged on the upper surface side of the metal cover 31. The upper wall 10 of the housing case 3 is arranged on the upper surface of the insulating member 38.

  The insulating member 39 is arranged on the upper surface of the upper wall 10. The metal plate 26 is arranged on the upper surface of the insulating member 39, and is electrically connected to the connection terminal 32.

  FIG. 4 is a cross-sectional view showing the configuration of the bottom plate 50 of the reversing plate 30 and its surroundings. A cutout portion 53 is formed in the peripheral wall portion 51. The thickness of the portion of the reversal plate 30 where the cutout portion 53 is located is smaller than the thickness of the other portion of the peripheral wall portion 51.

  The bottom plate 50 of the reversal plate 30 and the metal plate 33 are electrically connected. On the other hand, the upper plate 34C is disposed between the main wall portion 52 of the reversal plate 30 and the metal plate 33, and the main wall portion 52 and the metal plate 33 are not in direct contact with each other.

  The through hole 41 of the metal plate 33 is formed by a small diameter hole 55 and a large diameter hole 56. The small diameter hole 55 and the large diameter hole 56 are formed so as to communicate with each other, and the large diameter hole 56 is located above the large diameter hole 56.

  An opening 60 is formed at the upper end of the through hole 41, and an opening 61 is formed at the lower end of the through hole 41. The opening 60 is open toward the outside of the housing case 3, and the opening 61 is open inside the housing case 3.

  The bottom plate 50 of the reversal plate 30 is arranged so as to close the opening 60. A joint portion 62 is formed in a portion of the bottom plate 50 that is located around the bottom plate 50 and on the upper surface of the metal plate 33. The bottom plate 50 of the reversing plate 30 is joined to the metal plate 33 by the joining portion 62.

  1 and 2, when the internal pressure in the housing case 3 is a normal pressure value, the leg portion 37 of the collector terminal 7 and the metal plate 33, the reversal plate 30, the metal cover 31, the connection terminal 32, Through the metal plate 26, the positive electrode of the electrode body 2 and the electrode terminal 25 are electrically connected. As described above, the positive electrode of the electrode body 2 and the electrode terminal 25 are electrically connected to each other, and the current cutoff device 27 is provided in the electric path between the positive electrode of the electrode body 2 and the electrode terminal 25. The current interrupt device 22 is also provided in the electric path between the electrode terminal 20 and the negative electrode of the electrode body 2.

  In the power storage device 1 configured as described above, the internal pressure in the housing case 3 may increase due to overcharge.

  When the internal pressure in the housing case 3 becomes higher than a predetermined pressure value, the current interruption device 22 and the current interruption device 27 are activated. When the current interrupt device 22 operates, the electrical connection between the negative electrode of the electrode body 2 and the electrode terminal 20 is interrupted. When the current interrupt device 27 operates, the electrical connection between the positive electrode of the electrode body 2 and the electrode terminal 25 is interrupted.

  FIG. 5 is a sectional view showing a state in which the current interruption device 27 is driven. When the internal pressure in the housing case 3 rises, the main wall portion 52 of the reversing plate 30 receives the pressure in the housing case 3 through the through holes 40 and 43 and the through holes 42 and 45. The bottom plate 50 receives the internal pressure in the housing case 3 through the through hole 41.

  Since the internal pressure in the accommodation space 35 is low, the main wall portion 52 of the reversing plate 30 is deformed so as to bulge upward. In FIG. 4, the bottom plate 50 of the reversal plate 30 is joined to the metal plate 33 by the joining portion 62.

  The main wall portion 52 is deformed so as to bulge upward, while the bottom plate 50 is joined to the upper surface of the metal plate 33, so a tensile force is applied to the peripheral wall portion 51.

  When the internal pressure in the housing case 3 exceeds a predetermined value, the portion of the peripheral wall portion 51 where the cutout portion 53 is formed breaks. Furthermore, as the fractured part progresses, the fractured part opens greatly and the fractured part progresses annularly.

  By breaking the notch portion 53, the main wall portion 52 is largely deformed upward. When the main wall portion 52 is deformed upward, the openings of the through holes 43 and 45 of the upper plate 34C are opened.

  Then, the deactivator 36 leaks to the outside from the broken portion of the peripheral wall portion 51, and enters the housing case 3 through the through holes 43 and 40, the through holes 45 and 42.

  When the deactivating agent 36 flows into the housing case 3, the electrode body 2 and the like can be deactivated, and the high electrical energy state in the housing case 3 can be eliminated. In the present embodiment, cutout portion 53 is formed in peripheral wall portion 51, but the position where cutout portion 53 is formed is not limited to peripheral wall portion 51. For example, the cutout portion 53 may be formed in the main wall portion 52 or the like. That is, the notch 53 may be at a position where the deactivating agent 36 can enter the housing case 3 and the electrode body 2 can be deactivated by breaking the notch 53.

  Then, the broken portion of the cutout portion 53 extends over the entire circumference of the main wall portion 52, so that the main wall portion 52 is completely broken. When the main wall portion 52 is completely broken, the electrical connection between the bottom plate 50 and the main wall portion 52 is cut off.

  When the electrical connection between the bottom plate 50 and the main wall portion 52 is cut off, the electrical connection between the electrode terminal 25 and the positive electrode of the electrode body 2 shown in FIG. 1 is cut off. When the electrical connection between the electrode terminal 25 and the positive electrode of the electrode body 2 is cut off, the charging of the electrode body 2 can be stopped. As described above, in the current interrupt device 27, when the electrode body 2 is overcharged, the deactivator 36 can be supplied into the housing case 3 and the electrode terminal 25 and the electrode body 2 can be connected. The electrical connection of can be cut off.

  Although the configuration of the current interrupting device 27 has been described, the current interrupting device 22 has the same configuration as the current interrupting device 27. Thereby, when the electrode body 2 is overcharged, the electrical connection between the electrode terminal 20 and the electrode body 2 can be cut off, and the quenching agent can be supplied into the housing case 3. You can

  Results of comparison between the power storage device 1 according to the present embodiment shown in FIGS. 1 to 5 and the power storage device according to the comparative example will be described. The power storage device according to the comparative example does not include the deactivator 36.

  Table 1 below is a table showing the results when the power storage device 1 according to the example and the power storage device according to the comparative example are in an overcharged state.

  As shown in Table 1 above, in the electricity storage device 1 according to the present embodiment, the electricity storage device 1 can be deactivated and the current collector foil (the positive electrode foil (plate) and the negative electrode foil (plate)) can be used. It can be seen that the voltage between can be reduced. Further, according to the power storage device 1 according to the example, it is understood that smoke generation from the power storage device 1 can be suppressed and the temperature of the power storage device 1 can be suppressed from becoming high.

  FIG. 6 is a sectional view showing a current interruption device 27 according to Comparative Example 2. The current breaker 27A includes a reversal plate 70, a metal cover 31, a connection terminal 71, and a protrusion 72. The reversal plate 70 includes a thin portion 74, a bottom plate portion 75, a peripheral wall portion 76, and an upper wall portion 77. The thin portion 74 is formed at the center of the bottom plate portion 75. The peripheral wall portion 76 is formed so as to rise upward from the outer peripheral edge portion of the bottom plate portion 75. The upper wall portion 77 is connected to the upper end portion of the peripheral wall portion 76 and is formed so as to extend in the horizontal direction.

  The metal cover 31 is arranged outside the reversing plate 70 in the housing case 3. The metal cover 31 is arranged to press the outer peripheral edge of the reversing plate 70. A space 80 is formed between the metal cover 31 and the reversal plate 70.

  The connection terminal 71 is fitted in a hole formed in the upper wall of the metal cover 31. The lower end portion of the connection terminal 71 is formed so as to enter the space 80. A through hole is formed in the connection terminal 71. The opening on the upper end side of the through hole of the connection terminal 71 communicates with the outside of the housing case 3. The lower end side of the through hole of the connection terminal 71 is covered with the protrusion 72.

  The protrusion 72 is provided at the lower end of the connection terminal 71. The protrusion 72 includes a protrusion main body 78 and a mounting portion 79. The lower end portion of the protrusion main body 78 is formed in a needle shape, and is formed so as to extend downward. A through hole is formed in the protrusion body 78, and the through hole formed in the protrusion body 78 and the through hole formed in the connection terminal 71 are in communication with each other.

  The mounting portion 79 is arranged so as to cover the lower end portion of the protrusion 72 and is mounted on the inner peripheral surface of the metal cover 31.

  FIG. 7 is a cross-sectional view showing a state when the current cutoff device 27A operates in the power storage device including the current cutoff device 27A shown in FIG.

  When the internal pressure in the housing case 3 rises, the internal pressure in the housing case 3 is applied to the reversing plate 70, and the reversing plate 70 deforms so as to bulge upward.

  When the reversing plate 70 is deformed so as to bulge upward, the protrusion main body 78 penetrates the thin portion 74. With the protrusion main body 78 penetrating the thin portion 74, a deactivator is introduced through the opening of the connection terminal 71. As a result, the deactivation process can be performed in the housing case 3.

  Table 2 below is a table showing the results when the power storage device 1 according to the example and the power storage device according to the comparative example 2 are in the overcharged state.

  In Comparative Example 2, after the power storage device 1 is removed after the overcharged state, the deactivator is put in through the opening of the connection terminal 71.

  As is clear from Table 2 above, in the electricity storage device according to Comparative Example 2, the electricity storage device may reach a high temperature or smoke may be emitted from the electricity storage device 1 before the quenching agent is charged. On the other hand, in the electricity storage device 1 according to the present embodiment, the deactivation process can be performed immediately, so that the electricity storage device 1 can be prevented from reaching a high temperature and smoking from the electricity storage device 1.

  In the above embodiment, an example in which the electrode body 2 is used as the power storage element has been described, but a capacitor may be used as the power storage element.

  The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present disclosure is shown not by the above description but by the scope of the claims, and is intended to include meanings equivalent to the scope of the claims and all modifications within the scope.

  1 power storage device, 2 electrode body, 3 housing case, 4, 5 external terminal, 6, 7 current collecting terminal, 10 top wall, 11 bottom wall, 12, 13 main wall, 14, 15 end side wall, 20, 25 electrode terminal 21, 26, 33 metal plate, 22, 27, 27A current interrupting device, 30, 70 reversal plate, 31 metal cover, 32, 71 connection terminal, 34, 38, 39 insulating member, 34A vertical wall, 34B lower plate, 34C Upper plate, 34D Engagement part, 35 Housing space, 36 Deactivator, 37 Leg part, 40,41,42,43,44,45 Through hole, 46 Clamping part, 47,51,76 Peripheral wall part, 48 Heaven Plate part, 50 Bottom plate, 52 Main wall part, 53 Notch part, 55 Small diameter hole, 56 Large diameter hole, 60, 61 Opening part, 62 Joint part, 72 Protrusion part, 74 Thin wall part, 75 Bottom plate part, 77 Upper wall part , 78 Projection body, 79 Mounting , 80 space.

Claims (1)

Storage element,
A housing case for housing the power storage element,
A collector terminal provided in the housing case and connected to the power storage element,
An electrode terminal provided on the outer surface of the housing case and electrically connected to the collector terminal,
A current interrupting device provided in an electrical connection path between the collector terminal and the electrode terminal,
Equipped with
The current collector terminal has a through hole,
The first opening portion located at one end of the through hole is opened in the housing case,
The second opening located at the other end of the through hole opens toward the outside of the housing case,
The current interruption device,
A reversal plate covering the second opening,
A cover member that is provided so as to cover the reversal plate from the outside of the accommodating case with respect to the reversal plate and that forms a storage space between the reversal plate and the reversal plate;
A deactivator housed in the housing space,
Including,
The reversal plate has a joining portion joined to the current collecting terminal,
The reversal plate is formed so that the thickness of the reversal plate is thin, and a notch portion that breaks when the internal pressure in the housing case rises is formed,
The power storage device, wherein the cutout portion is formed at a position where the deactivator leaked from the cut portion of the cutout portion can flow into the housing case when the cutout portion is broken.

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