JP2014203745A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve reduced size in a power storage device in which a plurality of laminated power storage elements are sandwiched with an end plate from both sides in a lamination direction, and a circuit element is arranged at the outside of the end plate in the lamination direction.SOLUTION: An insulating end plate (18a) is superposed on the outside of a power storage element (14a) laminated at the most outside among laminated power storage elements (14), and a circuit element (32) is embedded into a recessed part (60) formed in the outside surface of the end plate. A metal plate (70) may be further superposed on the outside surface of the end plate (18a) in a part where the circuit element (32) is not interfered.

Description

  The present invention relates to a power storage device in which a plurality of power storage elements are electrically connected to form a module.

  Regarding a secondary battery such as a lithium ion battery, for example, a plurality of rectangular storage elements (battery cells) are stacked, and these storage elements are sandwiched between end plates from both sides in the stacking direction to form a stack, and the stack The battery module may be formed by sandwiching and fixing the battery from the outside of the end plate with a restraining band or the like. In this case, generally, the terminals of all the power storage elements are arranged on the same surface of the laminated body, specifically, on a surface parallel to the lamination direction, and these terminals are electrically connected via a bus bar or the like. By being connected, an electric circuit is formed.

  By the way, like a power storage device disclosed in Patent Document 1, circuit elements such as a circuit board and a fuse may be disposed on a surface different from a surface where a terminal of a power storage element is disposed in a stacked body.

  Specifically, referring to FIG. 7 to FIG. 9 of Patent Document 1, the stacked body of the power storage device includes a plurality of power storage elements stacked via resin spacers, and the outermost power storage elements on both sides in the stacking direction. And a metal end plate stacked on the outer side with a spacer interposed therebetween. The laminate is fixed by being sandwiched by bind bars from outside the end plates on both sides. Further, referring to FIGS. 9 and 10 of the same document, a substrate holder is stacked on the outer side of the end plate on one end side in the stacking direction, and a circuit board and a bus bar are fixed on the outer side of the substrate holder. . On the other hand, referring to FIGS. 8, 11, 12, etc. of the same document, on the other end side in the stacking direction, an electrical component holder is stacked on the outer side of the end plate, and a fuse and a shunt resistor are disposed on the outer side of the electrical component holder. The lead plate is fixed.

  According to the structure of Patent Document 1, a substrate holder or an electrical component holder is interposed between a metal end plate and a circuit element (circuit board, bus bar, fuse, shunt resistor and lead plate). The circuit elements can be electrically isolated from the metal end plate.

JP 2011-175743 A

  However, in the technique of Patent Document 1, since the substrate holder or the electrical component holder is overlaid on the outside of the laminated body (outside of the metal end plate), and the circuit elements are overlaid on the outside of the holder, There is a disadvantage that the size increases by the addition of the thickness of the holder and the thickness of the circuit element to the thickness of the laminate, leading to an increase in the size of the power storage device.

  Accordingly, the present invention aims to reduce the size of a power storage device in a power storage device in which a plurality of stacked power storage elements are sandwiched between end plates from both sides in the stacking direction and circuit elements are arranged outside the end plate in the stacking direction. This is the issue.

The power storage device according to the present invention includes:
A plurality of stacked power storage elements;
An insulating end plate stacked on the outside of the power storage element stacked on the outermost side among the plurality of power storage elements;
And a circuit element embedded in a recess formed on the outer surface of the end plate.

  According to the present invention, since the circuit element arranged outside the end plate in the stacking direction is embedded in the recess formed on the outer surface of the end plate, the protrusion of the circuit element outside the end plate is suppressed. can do. Therefore, it is possible to reduce the size of the power storage device with respect to the dimensions in the stacking direction while adopting a configuration in which circuit elements are arranged outside the end plate in the stacking direction.

  In addition, according to the present invention, in the manufacturing process, the circuit element positioned by being fitted in the recess of the end plate can be easily fixed to the end plate, so that productivity can be improved. Furthermore, since the circuit element is surrounded by the peripheral wall of the recess, the circuit element is unlikely to be displaced with respect to the end plate even if vibration or the like occurs after the manufacturing process and assembly.

  The power storage device according to the present invention may further include a metal plate overlaid on the outer surface of the end plate in a portion that does not interfere with the circuit element. In this case, the rigidity of the power storage device can be increased by overlapping the metal plate on the outer surface of the end plate. In this case, the metal plate is electrically insulated from the casing of the power storage element by interposing an insulating end plate between the casing of the power storage element stacked on the outermost side. At the same time, by overlapping the outside of the end plate in a portion that does not interfere with the circuit element, the circuit element is also electrically insulated. In this way, since electrical insulation between the casing, the circuit element, and the metal plate of the electricity storage element is performed only by the end plate, it is not necessary to further stack another insulator on the outside of the end plate. Furthermore, since the rigidity is ensured by the metal plate as described above, the thickness of the end plate itself can be reduced. Therefore, the power storage device can be reduced in size with respect to the dimension in the stacking direction while ensuring rigidity and electrical insulation.

  Preferably, the metal plate is embedded in a recess for a metal plate formed on an outer surface of the end plate separately from the recess. In this case, in the manufacturing process, since the metal plate positioned by being fitted into the recess for the metal plate of the end plate can be easily fixed to the end plate, productivity can be improved. Further, since the metal plate is surrounded by the peripheral wall of the recess for the metal plate, the metal plate is not easily displaced with respect to the end plate even if vibration or the like occurs after the manufacturing process and assembly. Furthermore, since the circuit element and the metal plate are reliably positioned with respect to the end plate, it is possible to reliably avoid contact between the circuit element and the metal plate, thereby more reliably electrically insulating the two. it can.

  In the present invention, the circuit element may be a bus bar or a shunt resistor. Since a high voltage is applied to the circuit element of the power storage device and a large current may flow through the bus bar or shunt resistor used as the circuit element, it is important to achieve reliable electrical insulation to prevent a short circuit. . According to the present invention, it is possible to reliably achieve electrical insulation of the bus bar or shunt resistor embedded in the recess of the end plate with respect to the metal plate and the casing of the power storage element as described above. Even if the recess of the end plate is relatively shallow, the plate-like bus bar and the shunt resistor can be easily fitted into the recess.

  In the present invention, the circuit element may be a fuse. Also in this case, the fuse can achieve good electrical insulation with respect to the metal plate and the casing of the power storage element. Furthermore, since an overcurrent can be interrupted by a fuse, a circuit breaker (for example, a relay unit) other than the fuse can be downsized or omitted.

  Furthermore, in the present invention, an insulating cover plate that covers at least a part of the circuit element from the outside may be fixed to the outside of the end plate. Thereby, since the circuit element arrange | positioned at the recessed part of an end plate is covered from an outer side with an insulating cover plate, a contact with a circuit element and a foreign material can be prevented effectively.

  In this case, only a part of the circuit element may be covered from the outside by the cover plate. Thereby, while protecting the part covered with the cover plate in the circuit element, if necessary, using the exposed part of the circuit element, maintenance of the circuit element, measurement of voltage or current (test), or another Connection work to circuit elements can be performed.

  Preferably, in the stacked body including the plurality of power storage elements and the end plate, an end surface on the end plate side in the stacking direction of the stacked body is arranged on the opening surface side in a case having an opening surface. Be contained. Thereby, since the end plate is positioned on the opening surface side of the case in a state where the laminated body is accommodated in the case, it is possible to easily perform maintenance or the like of the circuit elements positioned outside the end plate. it can.

  Preferably, the circuit element is provided along a peripheral edge portion of the end plate. Thereby, a metal plate can be piled up on most of the outer surface of the end plate, and high rigidity can be ensured.

  According to the present invention, since the circuit element is embedded in the recess formed on the outer surface of the end plate, the protrusion of the circuit element to the outside of the end plate can be suppressed. Therefore, it is possible to reduce the size of the power storage device with respect to the dimensions in the stacking direction while adopting a configuration in which circuit elements are arranged outside the end plate in the stacking direction.

It is a perspective view which shows the electrical storage apparatus which concerns on one Embodiment of this invention. It is a perspective view which shows the battery module of the electrical storage apparatus shown in FIG. FIG. 3 is an exploded perspective view showing a partially exploded view of a laminated body and a cover plate constituting the battery module shown in FIG. 2. It is a disassembled perspective view which shows the laminated body of an assembly | attachment state, and the cover plate of the state isolate | separated from this laminated body. It is a perspective view which shows the end plate provided with the recessed part for fuses, and a fuse regarding the electrical storage apparatus which concerns on another embodiment.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In order to facilitate understanding of the invention, in the accompanying drawings, some members not related to the present invention are not shown.

  As shown in FIG. 1, a power storage device 1 according to an embodiment of the present invention includes a battery module 10 as a device body and an outer case 2 that houses the battery module 10. The power storage device 1 is used as, for example, a relatively low voltage (for example, 12V) auxiliary battery mounted in a gasoline vehicle or a diesel vehicle, but the application of the power storage device 1 is not limited.

  The outer case 2 is installed in the posture shown in FIG. The exterior case 2 includes a box-shaped case body 2A having one opening surface, and a lid 2B that closes the opening surface of the case body 2A. In the use state shown in FIG. 1, the opening surface of the case body 2 </ b> A is disposed on the upper surface. The lid 2B is fixed to the case body 2A using, for example, screws in a state where the opening surface of the case body 2A is closed. On the upper surface of the lid 2B, a positive external terminal 99a and a negative external terminal 99b are provided so as to protrude.

  Hereinafter, the configuration of the battery module 10 will be described with reference to FIGS. 2 to 4, the battery module 10 is shown in a direction different from that in FIG. 1. Therefore, in the following description with reference to FIGS. 2 to 4, the terms including “upper”, “lower” and “lateral”, and the term “side” refer to the attitude of the battery module 10 shown in FIGS. The direction is shown, and the direction in the posture shown in FIG. 1 is not shown.

  As shown in FIG. 2, the battery module 10 is formed by modularizing battery cells 14 (14 a, 14 b, 14 c, 14 d, 14 e, 14 f, 14 g, 14 h) as a plurality of (for example, eight) power storage elements. Yes. The battery cell 14 is a secondary battery in which an electrode body and an electrolytic solution are accommodated in a flat rectangular casing. Specifically, the battery cell 14 is, for example, a lithium ion battery, but may be a secondary battery other than the lithium ion battery. On the upper surface of the battery cell 14, a positive terminal 22 a and a negative terminal 22 b are provided at both ends in the longitudinal direction, and a safety valve 24 is provided at the center in the longitudinal direction.

  The plurality of battery cells 14 are stacked in the thickness direction (D direction in the figure) of the battery cells 14 via resin spacers 16. By interposing the spacer 16 between the adjacent battery cells 14, the casings of the battery cells 14 are electrically insulated. In such a stacked state, the terminals 22 (22a, 22b) of the battery cells 14 are divided into two rows and arranged side by side in the stacking direction (D direction in the figure). In each row of terminals 22, two positive terminals 22a and two negative terminals 22b are alternately arranged.

  In one row of terminals 22, two negative terminals 22b on one end side in the stacking direction (D direction in the figure) are electrically connected to each other via a bus bar 28a, and two positive terminals 22a on the other end side are connected. They are electrically connected to each other via a bus bar 28e. In this row, the four terminals 22a and 22b in the middle part in the stacking direction (D direction in the figure) are electrically connected to each other via the bus bar 28c. In the other row of terminals 22, four terminals 22a and 22b on one end side in the stacking direction (D direction in the figure) are electrically connected to each other via a bus bar 28b, and four terminals 22a and 22b on the other end side are connected. 22b are electrically connected to each other via a bus bar 28d. With such a connection structure, four sets of parallel circuits including a pair of adjacent battery cells 14 are formed, and these parallel circuits are connected in series.

  The plurality of bus bars 28 (28a, 28b, 28c, 28d, 28e) connecting the terminals 22 of the battery cells 14 are unitized via a bus bar frame (not shown), and the plurality of battery cells 14 is attached.

  On both sides in the stacking direction (D direction in the figure), end plates 18a and 18b are provided on the outer sides of the outermost stacked battery cells 14a and 14h, respectively. Thereby, the laminated body 12 is formed by the pair of end plates 18a and 18b and the plurality of battery cells 14 and the plurality of spacers 16 sandwiched between the end plates 18a and 18b. The stacked body 12 is fixed so as to be sandwiched from both sides in the stacking direction by a plurality (for example, four) of metal restraining bands 50 (50a, 50b, 50c, 50d) (see FIGS. 3 and 4). ).

  In the use state shown in FIG. 1, the laminated body 12 is accommodated in the exterior case 2 in a direction in which the lamination direction (D direction in the figure) coincides with the vertical direction. In this accommodated state, the upper surface portion and the lower surface portion of the laminated body 12 are configured by the end plates 18a and 18b, so that the plurality of battery cells 14 are sandwiched from both sides in the vertical direction by the pair of end plates 18a and 18b. Thus, they are firmly fixed to each other. Further, in this accommodated state, the upper surface (the end surface on the one end plate 18a side in the stacking direction (D direction in the drawing)) of the stacked body 12 is disposed on the opening surface side of the case body 2A. Furthermore, when the power storage device 1 is mounted in an automobile or the like in the direction shown in FIG. 1, the plurality of battery cells 14 are stably supported by the lower end plate 18b.

  As shown in FIG. 2, a battery monitoring element 40 that monitors the power storage device 1 is provided on one side surface of the stacked body 12 parallel to the stacking direction (D direction in the drawing). The battery monitoring element 40 includes a relay unit 42 that interrupts overcurrent and a circuit board 44. The relay unit 42 and the circuit board 44 are fixed to the side surface of the multilayer body 12 via the base plate 41. The relay unit 42 is electrically connected to the positive electrode terminal 22a of the battery cell 14h stacked on the outermost side via the bus bar 28e and another bus bar 30. One end of a pair of bus bars 35, 36 is connected to the circuit board 44, the other end of one bus bar 35 is connected to the relay unit 42, and the other end of the other bus bar 36 is one end plate. It arrange | positions in the vicinity of 18a and is connected to the positive electrode external terminal 99a (refer FIG. 1).

  As shown in FIG. 3, a bus bar 32 for connecting the negative electrode terminal 22b of the outermost stacked battery cell 14a to the negative electrode external terminal 99b (see FIG. 1) is provided on the outer side of one end plate 18a. ing. The bus bar 32 is a strip-shaped metal plate extending in a straight line, and is disposed along the upper edge of the end plate 18a. Bolt insertion holes 33a and 33b are provided at both ends of the bus bar 32, and bolts for fixing the bus bar 32 to the end plate 18a are inserted into the bolt insertion holes 33a and 33b.

  One end of the bus bar 32 is bent in an L shape so as to straddle the upper surface of the laminated body 12 and the side surface of the laminated body 12 on the end plate 18a side with respect to the negative electrode terminal 22b of the battery cell 14a. (See FIG. 2). The other end of the bus bar 32 is connected to the negative external terminal 99b (see FIG. 1) via another bus bar (not shown). Since the end plate 18a to which the bus bar 32 is fixed is located on the opening surface side of the case main body 2A, the work of connecting the bus bar 32 to another bus bar, the work of replacing the bus bar 32, and the voltage or current using the bus bar 32 The measurement and the like can be easily performed through the opening surface of the case body 2A even when the laminate 12 is accommodated in the case body 2A.

  Further, a metal plate 70 is overlapped and fixed outside the one end plate 18a at a portion that does not interfere with the bus bar 32.

  As a material of the metal plate 70, it is preferable to use a metal material having higher strength than the bus bar 32. Although the metal plate 70 is substantially rectangular, a notch 74 for avoiding interference with the bus bar 32 is provided at the upper edge of the metal plate 70. Thereby, the upper edge part of the metal plate 70 has a shape in which both side portions sandwiching the notch 74 protrude upward. In the metal plate 70, for example, a pair of bulging portions 72 a and 72 b extending in the lateral direction are formed so as to bulge toward the end plate 18 a, thereby increasing the rigidity of the metal plate 70. The metal plate 70 is provided with a pair of bolt insertion holes 76. The weld bolt 15 is inserted into each bolt insertion hole 76 from the inside, and the weld bolt 15 is welded to the inner surface of the metal plate 70.

  In addition, the same metal plate 70 is similarly piled up and fixed to the outside of the other end plate 18b.

  The end plates 18a and 18b on both sides have the same configuration. Therefore, only the configuration of one end plate 18a will be described here.

  The end plate 18 a has a substantially rectangular shape corresponding to the shape of the battery cell 14. The end plate 18a is made of an electrically insulating material. Specifically, the material of the end plate 18a is, for example, resin, and can be easily molded as compared with the case where it is made of metal. At the peripheral edge of the end plate 18a, there are an engagement protrusion 69a that can be engaged with the engagement recess 19a of the spacer 16 stacked on the outermost side, and an engagement recess that can be engaged with the engagement protrusion 19b of the spacer 16. 69b.

  On the outer surface of the end plate 18a, a bus bar recess 60 as a bus bar holding portion for holding the bus bar 32 and a metal plate recess 64 as a metal plate holding portion for holding the metal plate 70 are formed. Has been.

  The bus bar recess 60 is formed to be elongated along the upper edge of the end plate 18a. Specifically, the shape of the bus bar recess 60 is an elongated rectangle slightly larger than the bus bar 32. The depth of the bus bar recess 60 is the same as or slightly smaller than the thickness of the bus bar 32. Therefore, when the bus bar 32 is accommodated in the bus bar recess 60, all or most of the bus bar 32 is embedded in the end plate 18a in the thickness direction. Circular recesses 62 are provided at both ends in the length direction of the bottom of the bus bar recess 60. By attaching nuts (not shown) to these recesses 62, bolts for fixing the bus bar 32 can be fastened to the nuts.

  The metal plate recess 64 has substantially the same shape as the metal plate 70 and is slightly larger than the metal plate 70. The metal plate recess 64 has a depth equal to or greater than the thickness of the metal plate 70. Therefore, when the metal plate 70 is accommodated in the metal plate recess 64, the entire metal plate 70 is embedded in the end plate 18a in the thickness direction. As described above, since the bus bar recess 60 is elongated along the upper edge of the end plate 18a, the metal plate recess 64 is formed larger in the remaining portion excluding the elongated bus bar recess 60. be able to. Therefore, the metal plate 70 can be overlaid on most of the outer surface of the end plate 18a, thereby ensuring high rigidity.

  The depth of the metal plate recess 64 is larger than the thickness of the metal plate 70. In addition, a pair of recesses 66 for accommodating the heads of the weld bolts 15 are further formed at the bottom of the metal plate recess 64.

  By accommodating the bus bar 32 in the bus bar recess 60 of the end plate 18a configured as described above and the metal plate 70 in the metal plate recess 64, the bus bar 32 is surrounded by the peripheral wall of the bus bar recess 60, and The metal plate 70 is surrounded by the peripheral wall of the metal plate recess 64, so that the bus bar 32 and the metal plate 70 are positioned reliably. Therefore, electrical insulation between the bus bar 32 and the metal plate 70 can be reliably achieved.

  In addition, a resin end plate 18a is interposed between the bus bar 32 and the casing of the battery cell 14a and between the metal plate 70 and the casing of the battery cell 14a, thereby being electrically insulated. .

  Thus, electrical insulation among the battery cell 14a, the bus bar 32, and the metal plate 70 is performed only by the end plate 18a. Therefore, in the laminated body 12, it is not necessary to further laminate | stack the insulator different from the end plate 18a, and the thickness of the laminated body 12 can be reduced.

  Moreover, since the metal plate 70 is fixed to the end plates 18a and 18b on both sides, the rigidity of the laminate 12 can be ensured satisfactorily even if the resin end plates 18a and 18b are used. Therefore, it is not necessary to increase the thickness of the end plates 18a and 18b itself. Further, since one end plate 18a is filled with all or most of the metal plate 70 and the bus bar 32 in the thickness direction, the metal plate 70 and the metal plate 70 from the end plate 18a in the stacking direction (D direction in the figure) The protrusion of the bus bar 32 is suppressed. Therefore, while the bus bar 32 is arranged as a circuit element on the outer side in the stacking direction (D direction in the drawing) of the stacked body 12, an increase in the thickness of the stacked body 12 due to this can be suppressed. The apparatus 1 can be downsized.

  A cover plate 20 that covers the bus bar 32 from the outside is provided on the outside of the end plate 18a, thereby preventing contact between the bus bar 32 and a foreign object.

  The cover plate 20 has a substantially rectangular shape corresponding to the shape of the end plate 18a. The cover plate 20 is made of an electrically insulating material. Specifically, the material of the cover plate 20 is, for example, a resin, and can be easily molded as compared with the case where it is made of metal. Since the end plate 18a is also made of resin as described above, the end plate 18a and the cover plate 20 can be formed into a shape that can suitably accommodate the bus bar 32 therebetween.

  On the peripheral edge of the cover plate 20, an engagement convex portion 89a that can be engaged with the engagement concave portion 79a of the end plate 18a is provided. The cover plate 20 is provided with a pair of bolt insertion holes 86 for allowing the weld bolts 15 to pass therethrough. A pair of peripheral wall portions 88 rising from the periphery of each bolt insertion hole 86 are provided on the outer surface of the cover plate 20. In addition, a plurality of recesses 90 are formed on the inner surface of the cover plate 20 to avoid interference with the ends of the restraining band 50.

  A first opening 82 for exposing one end of the bus bar 32 and a second opening 84 for exposing the other end of the bus bar 32 are provided at the upper edge of the cover plate 20. Thus, even when the cover plate 20 is attached to the end plate 18a, another bus bar can be connected to the exposed portion of the bus bar 32 through the first opening 82 and the second opening 84, or the exposed portion of the bus bar 32 can be connected. Can be used for maintenance or measurement (testing).

  However, the bus bar 32 is not necessarily provided with the first opening 82 and the second opening 84. When the first opening 82 or the second opening 84 is not provided, the connection work between the bus bar 32 and another bus bar may be performed with the cover plate 20 removed.

  Hereinafter, a procedure for assembling the battery module 10 will be described with reference to FIGS. 3 and 4.

  First, a plurality of battery cells 14 stacked with a spacer 16 in between are sandwiched from both sides in the stacking direction (D direction in the figure) by a pair of end plates 18a and 18b to form the stacked body 12. As shown in FIG. 3, when one end plate 18a is stacked on the outside of the battery cell 14a, the engagement protrusion 69a and the engagement recess 69b of the end plate 18a are engaged with the engagement recess 19a of the spacer 16. Engage with the convex portion 19b. Thereby, the end plate 18a is positioned with respect to the spacer 16 and the battery cell 14a.

  Subsequently, the metal plate 70 is stacked outside the end plates 18 a and 18 b so as to be accommodated in the metal plate recess 64. Thereby, the metal plate 70 is embedded in the end plates 18a and 18b. Here, the weld bolt 15 is welded in advance to the metal plate 70 to be overlaid on the one end plate 18a.

  Next, the laminate 12 is fixed using, for example, four restraining bands 50 (50a, 50b, 50c, 50d) so that the constituent members of the laminate 12 are not separated. Specifically, the restraint bands 50 are pressed against the outer peripheral portion of the spacer 16 and the outer peripheral portions of the end plates 18a and 18b on a plane parallel to the stacking direction (D direction in the drawing) of the stacked body 12, and the stacking direction (see FIG. The ends of the restraining band 50 bent at a right angle are pressed to the outside of the metal plate 70 at both end faces in the middle D direction) and fixed by, for example, bolts (not shown).

  Subsequently, the cover plate 20 is overlapped on the outer side of the end plate 18a in a state where the bus bar 32 is accommodated in the bus bar recess 60 of one end plate 18a and the bus bar 32 is embedded in the end plate 18a. At this time, the engagement convex portion 89a of the cover plate 20 is engaged with the engagement concave portion 79a of the end plate 18a to position the cover plate 20 with respect to the end plate 18a and to the bolt insertion hole 86 of the cover plate 20. The weld bolt 15 is inserted.

  In a state where the cover plate 20 is overlaid on the outside of the end plate 18 a, the tip of the weld bolt 15 protrudes outside the cover plate 20. As shown in FIG. 4, the cover plate 20 is fixed to the end plate 18 a by screwing and tightening a nut 17 to the protruding portion of the weld bolt 15. The nut 17 screwed into the weld bolt 15 is accommodated inside the peripheral wall portion 88 of the cover plate 20.

  Thereafter, one end portion of the L-shaped bus bar 34 is overlapped with an end portion of the bus bar 28a attached to the negative electrode terminal 22b of the battery cell 14a stacked on the outermost side, and is fixed by bolts or welding. Further, the other end portion of the L-shaped bus bar 34 is overlapped with one end portion of the bus bar 32 exposed in the first opening 82 of the cover plate 20, and the bolt insertion hole 33 a of the bus bar 32 and the L-shaped bus bar 34 are A bolt 39 inserted from the outside into the bolt insertion hole 31 is screwed into a nut (not shown) attached to the end plate 18a and tightened to fix the bus bars 32 and 34 to the end plate 18a. As a result, the bus bar 32 accommodated in the bus bar recess 60 of the end plate 18 a and the bus bar 30 not accommodated in the bus bar recess 60 are efficiently fixed to the end plate 18 a by fastening the same bolt 39. At this time, the bus bar 32 is embedded in the bus bar recess 60 so that the bus bar 32 is not displaced, so that the bolt can be easily and reliably fastened.

  Further, the other end of the bus bar 32 exposed at the second opening 84 of the cover plate 20 is fixed to the end plate 18a by fastening a bolt together with another bus bar (not shown). Thereafter, the negative external terminal 99b is connected to the bus bar fixed to the end plate 18a together with the bus bar 32. However, the other end portion of the bus bar 32 may be extended so as to protrude to the outside of the cover plate 20, and this extended portion may be directly connected to the negative electrode external terminal 99b.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, when the strength of the material of the metal plate 70 is higher than the material of the bus bar 32, the length of the bus bar 32 may be shortened, and the area of the metal plate 70 may be increased by that amount. Thereby, the rigidity of the battery module 10 is further enhanced. In this case, for example, the right side portion of the bus bar 32 in FIG. 4 is shortened and the portion extending in the direction perpendicular to the stacking direction of the bus bars 28a is extended, whereby both bus bars 28a and 32 are connected by the L-shaped bus bar 34. can do.

  Conversely, if the material of the bus bar 32 is stronger than the material of the metal plate 70, the length of the bus bar 32 may be expanded to reduce the area of the metal plate 70 by that amount. Thereby, the rigidity of the battery module 10 is further enhanced. In this case, for example, the right side portion of the bus bar 32 in FIG. 4 is extended, and the upper portion of the terminal 22b in the bus bar 28a is extended outward in the stacking direction (D direction in the drawing) so as to be arranged outside the end plate 18a. The bent portion can be connected to the right extended portion of the bus bar 32 by bending in an L shape.

  In the above-described embodiment, the configuration in which the bus bar 32 is accommodated in the recess 60 of the end plate 18a has been described. However, in the present invention, circuit elements other than the bus bar may be accommodated in the recess of the end plate.

  For example, instead of the bus bar 32, a shunt resistor may be accommodated in the recess 60 of the end plate 18a. Also in this case, the shunt resistor accommodated in the recess 60 can be reliably electrically insulated from the metal plate 70 and the casing of the battery installation 14a. Further, by using a plate-like shunt resistor, the shunt resistor can be easily accommodated in the recess 60 formed shallow on the surface of the end plate 18a.

  As yet another example, for example, as shown in FIG. 5, a fuse recess 160 may be provided on the outer surface of the end plate 18 a, and the fuse 100 may be accommodated in the fuse recess 160. In this case, the concave portion for fuse 160 may be formed so as to have a shape and depth corresponding to the shape of the fuse 100. According to this configuration, since the overcurrent can be interrupted by the fuse, the relay unit 42 can be downsized. When the fuse is blown, the fuse 2 can be easily replaced by removing the lid 2B of the outer case 2.

  Furthermore, in the above-described embodiment, the case where the upper surface of the case body 2A is an opening surface has been described. However, in the present invention, the side surface of the case body 2A may be an opening surface.

DESCRIPTION OF SYMBOLS 1 Power storage device 2 Exterior case 2A Case main body 2B Lid 10 Battery module (device main body)
12 Laminated body 14 Battery cell (electric storage element)
14a Battery cells stacked on the outermost side (storage element)
DESCRIPTION OF SYMBOLS 15 Weld bolt 17 Nut 18a One end plate 18b The other end plate 20 Cover plate 22a Battery cell positive terminal 22b Battery cell negative terminal 28 Bus bar which connects between battery cell terminals 32 Bus bar (circuit element)
34 Another bus bar 39 Bolt 42 Relay unit 44 Circuit board 50 Restraint band 60 Bus bar recess 64 Metal plate recess 70 Metal plate 82 First opening 84 Second opening 99a Positive external terminal 99b Negative external terminal 100 Fuse 160 For fuse Recess

Claims (9)

A plurality of stacked power storage elements;
An insulating end plate stacked on the outside of the power storage element stacked on the outermost side among the plurality of power storage elements;
And a circuit element embedded in a recess formed on the outer surface of the end plate.   The power storage device according to claim 1, further comprising a metal plate overlaid on an outer surface of the end plate at a portion that does not interfere with the circuit element.   The power storage device according to claim 2, wherein the metal plate is embedded in a recess for a metal plate formed on an outer surface of the end plate separately from the recess.   The power storage device according to any one of claims 1 to 3, wherein the circuit element is a bus bar or a shunt resistor.   The power storage device according to any one of claims 1 to 3, wherein the circuit element is a fuse.   The power storage device according to any one of claims 1 to 5, wherein an insulating cover plate that covers at least a part of the circuit element from the outside is fixed to the outside of the end plate. .   The power storage device according to claim 6, wherein only part of the circuit element is covered from the outside by the cover plate.   The stacked body including the plurality of power storage elements and the end plate is accommodated in a case having an opening surface such that an end surface on the end plate side in the stacking direction of the stacked body is disposed on the opening surface side. The power storage device according to claim 1, wherein the power storage device is a power storage device.   The power storage device according to any one of claims 1 to 8, wherein the circuit element is provided along a peripheral edge portion of the end plate.

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