JP5290662B2 - Battery module external short circuit system - Google Patents

Description

  The present invention relates to a system for externally short-circuiting an abnormal battery in a battery module formed by connecting a large number of secondary batteries.

  Conventionally, various rechargeable secondary batteries used mainly as a power source for portable devices have been proposed. Furthermore, in recent years, a battery equipped with a rechargeable battery has been developed for vehicles such as automobiles and trains in consideration of the environment. When a secondary battery is mounted on a vehicle, regenerative power generated during braking can be stored in the mounted battery and used as a power source for the vehicle, so that the energy efficiency of the vehicle can be increased. Thus, as a secondary battery mounted on a vehicle, for example, a nickel hydride secondary battery is considered suitable from various conditions such as energy density, durability, and manufacturing cost (Patent Document 1). As described above, when a battery is used as a power source of a vehicle, a high voltage is required. Therefore, it is necessary to configure a battery module in which a large number of unit batteries are connected in series.

  In a battery module configured by connecting a large number of batteries in series, there is a variation in the degree of performance deterioration between the unit batteries in the process of repeating the charge / discharge cycle, and a state in which the balance of the charge / discharge capacity is greatly lost occurs. There is. If a battery module is charged / discharged in a state where a unit battery with extremely deteriorated charge / discharge capacity compared to other unit batteries is generated, the deteriorated unit battery will be overcharged or overdischarged. It becomes difficult to maintain the performance.

  In such a case, it is preferable from the viewpoint of maintaining the performance of the battery that the voltage of each unit battery is monitored and the use of the battery-equipped device is stopped when an abnormal battery having extremely deteriorated capacity is detected. . However, from the viewpoint of a device equipped with a battery module, for example, in a vehicle used as a transportation facility, it may be inconvenient for the passenger to stop the operation of the device suddenly. Even if detected, it may be necessary to continue driving for a while. Therefore, it is conceivable that the positive terminal and the negative terminal of the abnormal unit battery are externally short-circuited and the operation of the vehicle is continued using substantially only the remaining unit battery.

  However, when such a method is used, each unit battery remaining in the battery module is charged with an excessive charge / discharge voltage for the amount of one cell removed, so that it is particularly difficult to maintain performance against overcharge / overdischarge. In the lithium ion secondary battery, the method of externally short-circuiting the abnormal battery cannot be applied. In addition, even for alkaline secondary batteries such as nickel metal hydride batteries, if the discharge current is small, unit batteries with extremely deteriorated capacity can be electrically However, it is not practical in terms of circuit dimensions and cost to design a circuit that can withstand a large current in an application that is discharged with a large current, such as a vehicle application.

JP 2001-110381 A

  An object of the present invention is to solve the above-mentioned problems, and in a battery module configured by connecting a large number of unit cells in series, it is possible to reliably externally short-circuit a unit cell whose charge / discharge capacity has greatly deteriorated with a simple structure. It is providing the external short circuit system which can ensure operation | movement of the vehicle by which a battery module is mounted.

  In order to achieve the above-described object, an external short-circuit system for a battery module according to the present invention includes a plurality of unit batteries configured as a square alkaline secondary battery and connected in series, and a plurality of plate-like conductive members. A battery laminate formed by alternately laminating, and a short-circuit member for short-circuiting between the positive electrode current collector plate and the negative electrode current collector plate provided facing each other in the stacking direction of the battery laminate in the unit battery The conductive member is formed with an engagement hole extending perpendicularly to the stacking direction of the battery stack, and the short-circuit member includes a plate-shaped main body and the unit protruding from the main body. It has an engaging protrusion which engages with each engaging hole of the two said electrically-conductive members adjacent via a battery.

  According to this configuration, the plate-shaped conductive member having the engagement hole is interposed between the unit cells constituting the battery module, and the engagement protrusion that engages with the conductive member and the engagement hole of the conductive member is provided. The unit battery can be externally short-circuited through the external short-circuit member. Therefore, by simply adding a conductive member and an external short-circuit member having a simple structure to the battery module, an abnormal unit battery can be reliably short-circuited externally to ensure operation of the vehicle on which the battery is mounted. Moreover, by changing the materials and dimensions of the conductive member and the external short-circuit member, it is possible to easily construct an external short-circuit system according to the discharge conditions of the device on which the battery module is mounted. In addition, since the system is applied to an alkaline secondary battery such as a nickel metal hydride secondary battery that has a relatively high safety against overcharge / overdischarge, it is 1 as an emergency measure when an abnormal unit battery is detected. Even if only the cell is externally short-circuited, the performance of the battery module can be ensured without greatly affecting the remaining unit batteries.

  In the above external short-circuit system according to the present invention, each of the positive electrode current collector plate and the negative electrode current collector plate of the unit cell has a bent portion that is bent in the opposite direction, and the short-circuit member includes It is preferable that the main body portion of the short-circuit member is engaged with the two conductive members so as to directly contact the bent portions of the positive electrode current collector plate and the negative electrode current collector plate. By constructing in this way, the contact area between the short-circuit member and the battery stack is increased by externally short-circuiting not only through the conductive member in contact with the unit battery, but also through the current collector plate of the unit battery, resulting in greater discharge. It becomes possible to cope with current.

  Further, in the above external short-circuit system according to the present invention, the positive electrode current collector plate and the negative electrode current collector plate of the unit battery each have a bent portion that is bent in the opposing direction, and the short-circuit member is The main body portion of the short-circuit member may be engaged with the two conductive members so as to come into contact with the bent portions of the positive electrode current collector plate and the negative electrode current collector plate via a conductive buffer member. Good. If comprised in this way, since the contact resistance between the main-body part of a short circuit member and each bending part of a current collecting plate can be reduced, it becomes possible to respond to a larger discharge current.

  In the external short-circuit system, a plurality of engagement holes of the conductive member are formed in the side surface of the plate-shaped conductive member, and the short-circuit member includes a plurality of the engagement protrusions and each engagement member. A plurality of notches formed between the mating protrusions, and each of the plurality of engaging protrusions and notches is provided at a position corresponding to one of the plurality of engaging holes of the conductive member. Also good. By setting the short-circuit member in such a structure, if necessary, the short-circuit member is attached to the conductive member in a state where a part of the plurality of engagement holes is not blocked, or a plurality of short-circuit members as described later. It is possible to select whether or not to attach to the conductive member.

  When the notch is provided in the short-circuit member as described above, the external short-circuit system further includes an engagement protrusion that engages with the engagement hole of the conductive member via the notch provided in the short-circuit member. And one or more additional short-circuit members attached to the conductive member in a state of being superimposed on the short-circuit member. By comprising in this way, it becomes possible to reduce the electrical resistance of a short circuit member and to carry out an external short circuit more effectively also to a large current.

  In the external short circuit system, the engagement hole of the conductive member is preferably formed as a vent hole penetrating in a direction orthogonal to the thickness direction of the conductive member. By comprising in this way, a current collection member can be utilized as a heat sink for cooling a unit battery. As a result, by cooling the unit battery in the battery module and suppressing the battery temperature rise at the time of charging / discharging, it is possible to more reliably secure the performance of the battery module by suppressing the variation in capacity deterioration between the unit batteries. .

  In the external short circuit system, all the engagement holes of the conductive member may be blocked by the engagement protrusions of the short circuit member. Here, “all the engagement holes are blocked by the engagement protrusions of the short-circuit member” means not only by the engagement protrusions of one short-circuit member but also by the engagement protrusions of a plurality of short-circuit members. The case where all the engagement holes of the current collecting member are closed is included. The engagement hole of the battery module in the external short circuit system according to the present invention does not directly participate in charging / discharging of the battery module. Therefore, when the unit battery is externally short-circuited as an emergency measure when an abnormal unit battery is generated, including the case where the engagement hole is formed as a ventilation hole for battery cooling as described above, By engaging the engaging protrusions in all the engaging holes, the short-circuit member can be securely attached to the current collecting member, and the contact resistance between the short-circuit member and the current collecting member is reduced, resulting in a large current. It is possible to short-circuit externally more effectively.

  It is preferable that the thickness of the main body portion of the short-circuit member and the dimension in the stacking direction of the engagement holes of the conductive member are substantially the same. By configuring in this way, after the short-circuit member is cut out from the material having a uniform thickness, it can be created by bending the engaging projection from the main body, so that the short-circuit member can be easily and inexpensively manufactured. it can.

  As described above, according to the external short circuit system of the battery module according to the present invention, in a battery module configured by connecting a large number of unit batteries in series, a unit battery having a greatly deteriorated charge / discharge capacity can be obtained with a simple structure. By reliably short-circuiting externally, the operation of the vehicle on which the battery module is mounted can be ensured.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments.

  FIG. 1 is a partially broken side view showing a structure of a battery module B constituting an external short-circuit system according to an embodiment of the present invention. The battery module B is mounted on a train, for example, and is formed by alternately stacking unit batteries C that are rectangular batteries and conductive plates 3 that are plate-like conductive members in the longitudinal direction X that is the thickness direction. The battery stack 1 is provided as a main component, and the battery stack 1 is covered with a housing 5 made of an insulating material.

  FIG. 2 is a partially broken plan view showing an example of the structure of the unit battery C shown in FIG. The unit cell C includes a separator 11, an electrode body 17 including a positive electrode 13 and a negative electrode 15, and a rectangular casing 19 that houses the electrode body 17 together with an electrolytic solution. The casing 19 includes a rectangular frame-shaped member 21 made of an insulating material, and a first lid member 23 and a second lid member 25 made of a conductive material that face each other and cover the two openings of the frame-shaped member 21. Has been.

  The first lid member 23 and the second lid member 25 respectively have flat plate-like main body portions 23a and 25a that cover both openings of the frame-shaped member 21, and are integrated with each other on the four sides of the main body portions 23a and 25a. The bent portions 23b and 25b that cover a part of the outer peripheral surface of the frame-shaped member 21 are formed by bending the edge portions formed on the outer peripheral surface of the frame-shaped member 21 in the opposing directions.

  The structure of the electrode body 17 is not particularly limited. For example, a stacked structure in which a plurality of positive electrodes 13 and a plurality of negative electrodes 15 are alternately stacked in a predetermined direction via separators 11 bent in a pleat shape. have. The first lid member 23 and the second lid member 25 of the casing 19 are made of nickel-plated steel plates. The positive electrode 13 is electrically connected to the first lid member 23, and the negative electrode 15 is electrically connected to the second lid member 25. Connected. That is, the first and second lid members 23 and 25 also serve as the positive electrode current collector plate and the negative electrode current collector plate of the unit battery C, respectively.

  The unit battery C is provided with a voltage monitoring terminal 31 for monitoring the voltage of the unit battery C. The voltage monitoring terminals 31 may be provided in a pair, that is, one each on the positive electrode side and the negative electrode side, but one terminal 31 is provided on the positive electrode side and the negative electrode side of the adjacent unit battery C in the battery module B. It is preferable to share.

  Next, the structure of the battery laminated body 1 comprised using the unit battery C is demonstrated. As shown in FIG. 3, the battery stack 1 in the present embodiment is obtained by alternately stacking a plurality of unit batteries C and conductive plates 3. In the unit cell C, one first lid member 23 and the other second lid member 25 of the unit cells C adjacent to each other via the conductive plate 3 are stacked in a direction facing each other.

  Since the conductive plate 3 is interposed between the first lid member 23 that is one positive electrode current collector of the adjacent unit battery C and the second lid member 25 that is the other negative electrode current collector, In order to electrically connect the unit cells C in series, the unit cells C are formed of a material having electrical conductivity. In this respect, since aluminum has a relatively low electrical resistance and a relatively high thermal conductivity, aluminum has preferable characteristics as a material for forming the conductive plate 3. However, since aluminum easily oxidizes and contact resistance tends to increase, the contact resistance is reduced by applying nickel plating to the aluminum plate.

  As shown in FIG. 3A, which is a plan view showing the battery stack 1, the conductive plate 3 has an opening on one of the four side surfaces 3 a or both the upper side surface and the lower side surface, A plurality of engagement holes 3b having a substantially rectangular cross-sectional shape are formed. The plurality of engagement holes 3b are formed by a plurality of engagement holes 3b and the positions in the row direction of the engagement hole row L extending in the left-right direction Y are the engagement holes of the voltage monitoring terminal 31 of the unit battery C. It arrange | positions so that it may not overlap with the position of the row | line | column L direction.

  Further, as shown in FIG. 3B, which is a side view of the battery stack 1, the engagement holes 3 b of the conductive plates 3 are formed as holes extending in the vertical direction perpendicular to the stacking direction X of the battery stack 1. Has been. Further, among the plurality of conductive plates 3, each engagement hole 3 b of the conductive plate 3 excluding the conductive plates 3 and 3 positioned at both ends in the stacking direction X penetrates the conductive plate 3 in a direction orthogonal to the stacking direction X. It is formed as a vent 3bB. By passing cooling air sent from an electric fan (not shown) provided in the battery module B through the air vent 3b, the conductive plate 3 provided with the air vent 3bB cools the unit cells C located on both sides thereof. It functions as a heat sink. On the other hand, the conductive plates 3 and 3 positioned at both ends in the stacking direction X function as current collector plates on the positive electrode side and the negative electrode side of the entire battery stack 1, respectively.

  Next, a short-circuit member that is one of the main components of the external short-circuit system according to the present embodiment will be described. FIG. 4 is a perspective view showing an example of a short-circuit member used in the present embodiment. The short-circuit member 51 is configured by projecting a plurality of engaging protrusions 51b on a plate-like main body 51a. The main body 51a has a rectangular parallelepiped shape, and the engagement protrusion 51b has a rectangular column shape with a rectangular cross section. FIG. 5 shows a state in which the short-circuit member 51 is attached to a unit composed of one unit battery C and current collector plates 3 and 3 located on both sides thereof, which is a main part of the external short-circuit system S according to this embodiment. . As shown in FIG. 5A, which is a front view, the position and shape of each engagement protrusion 51 b are set so as to engage with the engagement hole 3 b of the conductive plate 3. Further, the short-circuit member 51 is formed of a conductive material, and as shown in FIG. 5B which is a side view, each engagement protrusion 51b is adjacent to two conductive plates 3 with the unit battery C interposed therebetween. , 3 are engaged with each other, the first lid member 23 that is the positive electrode current collector of the unit battery C and the second lid member 25 that is the negative electrode current collector are short-circuited.

  The short circuit between the first lid member 23 and the second lid member 25 of the unit battery C may be performed only through the two conductive plates 3 and 3, but in this embodiment, FIG. As shown, the lower surface of the main body 51 a of the short-circuit member 51 is in direct contact with the upper surfaces of both the bent portions 23 b and 25 b of the first and second lid members 23 and 25.

  Alternatively, as shown in FIG. 6, a conductive buffer member 53 may be interposed between the main body 51 a of the short-circuit member 51 and the first lid member 23 and the second lid member 25 of the unit battery C. In the present embodiment, nickel metal cotton is used as the conductive buffer member 53, but in addition to this, a conductive resin, a conductive paste, or the like can be used.

  In the external short-circuit system in the present embodiment, as the short-circuit member 51 shown in FIG. 5B, the thickness t1 of the main body 51a is substantially the same as the dimension X in the stacking direction X of the engagement holes 3b of the conductive plate 3. I am using what I did. In this case, even if the short-circuit member 51 is cut out from a material having a uniform thickness and then the engagement protrusion 51b is formed by bending from the main body 51a, the dimension t2 of the engagement protrusion 51b in the stacking direction X is set. The engagement hole 3b can be made to substantially coincide with the stacking direction X dimension l. Therefore, the short-circuit member 51 can be manufactured easily and inexpensively.

  Next, an external short-circuit system according to another embodiment of the present invention will be described. In this embodiment, the structure of the short-circuit member 51 is changed in the above-described embodiment described with reference to FIGS. 1 to 6, and the other configurations are the same as those in the embodiment shown in FIGS.

  As shown in FIG. 7, the short-circuit member 51 used in the present embodiment has a notch 51 c between a plurality of engaging protrusions 51 b that protrude from the main body 51 a. Each notch 51c is formed as a groove penetrating through the main body 51a in the thickness direction. When the short-circuit member 51 is attached to the conductive plate 3, as shown in FIG. It is arranged at a position corresponding to any one of 3b. The cross-sectional dimension of each notch 51 c is set to be substantially the same as or larger than the cross-sectional dimension of the engagement hole 3 b of the conductive plate 3.

  As described above, the conductive plate 3 functions as a heat radiating plate for cooling the unit cell C by using the engagement hole 3b as a cooling air vent. When it is desired to maintain the function as a heat sink to some extent for the unit battery C positioned at the position C, a part of the plurality of vent holes 3b is opened without being blocked by the short-circuit member 51 by providing the notch 51c.

  In addition, when priority is given to securing the amount of external short circuit current over cooling of the unit battery C in which an abnormality has occurred, it is added to the first short circuit member 51A directly attached to the conductive plate 3, as shown in FIG. Thus, the second short-circuit member 51B can be attached to the conductive plate 3 in a state of being superimposed on the first short-circuit member 51A. That is, the engagement protrusions 51 </ b> Bb of the additional second short-circuit member 51 </ b> B are connected to the conductive plate 3 via the notches 51 </ b> Ac of the first short-circuit member 51 </ b> A disposed at a position corresponding to the engagement hole 3 b of the conductive plate 3. It can be engaged with the engagement hole 3b. In this state, the position and posture of the second short-circuit member 51B are stabilized when the main body portion 51Ba comes into contact with the main body portion 51Aa of the first short-circuit member 51A. Note that the number of additional short-circuit members 51B that are engaged with the conductive plate 3 while being superimposed on the first short-circuit member 51A is not limited to one, and may be plural.

  Next, the operation of the external short-circuit system according to each embodiment of the present invention described above will be described.

  In the battery module B shown in FIG. 1, when a battery voltage abnormality such as overcharge or overdischarge is detected in any of the unit batteries C constituting the battery stack 1, the upper part of the housing 5 is removed, 5, the engagement protrusions 51b of the short-circuit member 51 are engaged with the conductive members in the engagement holes 3b and 3b of the two conductive plates 3 and 3 disposed on both sides of the unit battery C in which an abnormality is detected. Combine. At this time, the main body 51a of the short-circuit member 51 pushes the short-circuit member 51 to a position where it contacts the bent portions 23b and 25b of the first and second lid members 23 and 25 of the unit battery C. Alternatively, as shown in FIG. 6, a conductive buffer member 53 is interposed between the main body 51 a and the bent portions 23 b and 25 b, so that the main body 51 a and the conductive buffer member 53 of the short-circuit member 51 and the conductive The buffer member 53 and the bent portions 23b and 25b of the unit battery C push the short-circuit member 51 to a position where they sufficiently contact each other.

  In the present embodiment, the battery module B is mounted by reliably short-circuiting the abnormal unit battery C by simply adding the conductive plate 3 and the short-circuit member 51 having a simple structure to the battery module B as described above. The operation of the device can be ensured. In addition, by changing the materials and dimensions of the conductive plate 3 and the external short-circuit member 51, it is possible to easily construct an external short-circuit system according to the discharge conditions of the device on which the battery module B is mounted.

  Furthermore, since the short-circuit member 51 is brought into contact with the first and second lid members 23 and 25 that function as the positive and negative current collectors of the unit battery C directly or via the conductive buffer member 53, the unit battery By externally short-circuiting not only through the conductive plate 3 in contact with C but also through the current collector plate of the unit battery C, the contact area between the short-circuit member 51 and the unit battery C increases, and a larger discharge current can be accommodated. It becomes possible.

  Moreover, in other embodiment which concerns on this invention, as shown in FIG. 7, the short circuit member 51 which has the notch 51c extended in the thickness direction at the main-body part 51a is used. As shown in FIG. 8, when the engagement hole 3 b of the conductive plate 3 is used as a cooling air ventilation hole to function as a heat radiating plate for cooling the unit battery C, the short-circuit member 51 in this embodiment is used alone. If used, a part of the plurality of engagement holes 3 b of the conductive plate 3 is not blocked by the short-circuit member 51, and the function as a heat sink can be maintained.

  In addition, when priority is given to securing the amount of external short circuit current over cooling of the unit battery C in which an abnormality has occurred, it is added to the first short circuit member 51A directly attached to the conductive plate 3, as shown in FIG. Thus, by attaching the second short-circuit member 51B to the conductive plate 3 in a state of being superimposed on the first short-circuit member 51A, it is possible to reduce the electrical resistance of the entire short-circuit member and cope with a large discharge current. become.

  In any of the above embodiments, all the engagement holes 3b of the conductive member 3 are closed by the respective engagement protrusions 51b of the short-circuit member 51 (or the first and second short-circuit members 51A and 51B). can do. The engagement hole 3b of the battery module B does not directly participate in charging / discharging of the battery module B. Accordingly, the unit battery C is externally short-circuited as an emergency measure when an abnormality occurs in the unit battery C, including the case where the engagement hole 3b is formed as a ventilation hole for battery cooling as described above. In the case of making it, the shorting member 51 can be securely attached to the current collecting plate 3 by engaging the engaging projections with all the engaging holes 3 b, and between the shorting member 51 and the current collecting plate 3. The contact resistance can be reduced, and external short-circuiting can be more effectively performed even for a large current.

  Note that the number and shape of the engagement holes 3b formed in the conductive plate 3 are not limited to those described above, and may be appropriately changed according to the application and specifications of the device in which the battery module B is used. Furthermore, the number and shape of the engagement protrusions 51b and the notches 51c of the short-circuit member 51 can also be changed according to the number and shape of the engagement holes 3b.

  As described above, the preferred embodiments of the present invention have been described with reference to the drawings, but various additions, modifications, or deletions can be made without departing from the spirit of the present invention. Therefore, such a thing is also included in the scope of the present invention.

It is a partially broken side view which shows the battery module in the external short circuit system which concerns on one Embodiment of this invention. FIG. 2 is a partially broken plan view showing a unit battery in the battery module of FIG. 1. It is a schematic block diagram which shows the battery laminated body in the battery module of FIG. 1, (a) is a top view of a battery laminated body, (b) is a side view of a battery laminated body. It is a perspective view which shows the short circuit member in the external short circuit system which concerns on one Embodiment of this invention. It is a figure which shows the principal part of the external short circuit system which concerns on this embodiment, (a) is a front view which shows the state which attached the short circuit member of FIG. 4 to the electrically-conductive board, (b) is the side view. It is a side view which shows the modification of the structure which attaches the short circuit member of FIG. 4 to a conductive plate. It is a perspective view which shows the short circuit member in the external short circuit system which concerns on other embodiment of this invention. It is a front view which shows the state which attached the short circuit member of FIG. 7 to the electrically-conductive board. It is a front view which shows the state which piled up the two short circuit members of FIG. 7, and was attached to the electrically-conductive board.

Explanation of symbols

1 battery stack 3 conductive plate (conductive member)
3b Engagement hole 23 1st cover member (positive electrode current collecting plate)
25 Second lid member (negative current collector)
51 Short-circuit member 51a Main body 51b Engagement protrusion C Unit battery B Battery module S External short-circuit system

Claims (8)

A battery stack formed by alternately stacking a plurality of unit batteries configured as a prismatic alkaline secondary battery and connected in series, and a plurality of plate-like conductive members, and a stack of battery stacks in the unit battery A short-circuit member for short-circuiting between the positive electrode current collector plate and the negative electrode current collector plate provided to face each other in the direction,
The conductive member is formed with an engagement hole extending perpendicular to the stacking direction of the battery stack,
The short-circuit member has a plate-shaped main body portion, and an engagement protrusion that is provided on the main body portion and engages with each engagement hole of the two conductive members adjacent to each other via the unit battery.
Battery module external short circuit system.   In Claim 1, each of the positive electrode current collector plate and the negative electrode current collector plate of the unit battery has a bent portion that is bent in a direction opposite to each other, and the short-circuit member includes a main body portion of the short-circuit member. An external short-circuit system for a battery module that is engaged with the two conductive members so as to be in direct contact with the bent portions of the positive current collector and the negative current collector.   In Claim 1, each of the positive electrode current collector plate and the negative electrode current collector plate of the unit battery has a bent portion that is bent in a direction opposite to each other, and the short-circuit member includes a main body portion of the short-circuit member. An external short-circuit system for a battery module that is engaged with the two conductive members so as to come into contact with the bent portions of the positive electrode current collector plate and the negative electrode current collector plate via a conductive buffer member.   4. The engagement hole of the conductive member according to claim 1, wherein a plurality of engagement holes of the conductive member are formed in a side surface of the plate-like conductive member, and the short-circuit member includes a plurality of the engagement members. And a plurality of notches formed between the engaging protrusions. Each of the plurality of engaging protrusions and the notches corresponds to one of the plurality of engaging holes of the conductive member. An external short-circuit system for the battery module provided at the position.   5. The apparatus according to claim 4, further comprising an engagement protrusion that engages with an engagement hole of the conductive member through a notch provided in the short-circuit member, and is attached to the conductive member in a state of being superimposed on the short-circuit member. A battery module external short circuit system comprising one or more additional short circuit members.   The battery module external short-circuit system according to any one of claims 1 to 5, wherein the engagement hole of the conductive member is formed as a vent hole penetrating in a direction orthogonal to a thickness direction of the conductive member.   The battery module external short-circuit system according to claim 1, wherein all the engagement holes of the conductive member are closed by the engagement protrusions of the short-circuit member.   8. The external short circuit system for a battery module according to claim 1, wherein the thickness of the main body of the short circuit member and the dimension of the engagement hole of the conductive member in the stacking direction are substantially the same.

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