JP6176369B2 - Power supply - Google Patents

Description

  The present invention relates to a power supply device including a plurality of battery cells.

  A power supply device used for a hybrid car, an electric vehicle, a large power storage device, and the like is required to have a high voltage output and a high current capacity. As this type of power supply device, there is a power supply device formed by stacking a plurality of battery cells. The output voltage of the power supply device is increased by connecting the battery cells in series, and the current of the power supply device is connected by connecting in parallel. The capacity can be increased. As the battery cell constituting the power supply device, a secondary battery is used so that it can be repeatedly charged and discharged.

  In the secondary battery, the battery cell expands by repeating charge and discharge, and the battery performance (input / output characteristics) deteriorates due to the expansion. Therefore, in a power supply device configured by stacking a plurality of battery cells, a fastener that prevents expansion of the battery cells by fastening the battery cells in a pressurized state and suppresses deterioration of battery performance due to expansion. There is a power supply equipped.

  As this type of power supply device, for example, as a battery cell, a battery block formed by alternately stacking a rectangular battery having a rectangular parallelepiped outer can and a separator for holding the rectangular battery, and arranged at both ends of the battery block. There is known a power supply device including a pair of end plates provided, and a bind bar that is laid on the end plates and fastened in a state where the stacked rectangular batteries are pressed in the stacking direction (Patent Document 1). . According to this configuration, by fastening the battery block via the bind bar, the outer can of each rectangular battery is pressed by the adjacent separator, and the expansion of the outer can is suppressed. Specifically, since the size of the prismatic battery is limited by the bind bar erected on the end plate, even if the internal pressure in the outer can rises by repeating charging and discharging, the separator becomes wider in the outer can. Pressing the surface prevents the outer can from expanding.

  On the other hand, deterioration of battery performance is also affected by the life of the battery cell (increase in internal resistance due to aging, etc.). Specifically, the life of the battery cell is reduced by using the battery cell at a high temperature. For this reason, in addition to the above-described configuration, the power supply device of Patent Document 1 includes an outer can made of metal to improve the heat dissipation performance of the battery cell, and each battery cell via a cooling plate that contacts the lower part of the battery block. It can be cooled.

  When a metal outer can is used, a potential difference is generated in the outer can of adjacent battery cells, so that adjacent battery cells need to be insulated from each other. Further, in a power supply device provided with a cooling mechanism such as a cooling plate, it is necessary to insulate adjacent battery cells because dew condensation water may adhere to an outer can or the like due to a temperature difference from the surroundings. In the power supply device disclosed in Patent Literature 1, adjacent battery cells are insulated by disposing an insulating separator between adjacent battery cells.

JP 2011-34775 A

In the power supply device of Patent Document 1, the separator is configured to insulate adjacent battery cells and press the outer can of the battery cell via the bind bar to prevent the outer can from expanding.

  However, in the configuration of Patent Document 1, the separator is configured to uniformly press the wide surface of the outer can, and the optimum shape of the separator for efficiently suppressing deterioration of the battery performance of the rectangular battery due to expansion is sufficient. Therefore, it has been desired to efficiently prevent the expansion of the rectangular battery.

  The present invention has been made to solve such a problem, and provides a power supply device capable of suppressing deterioration of battery performance in a power supply device formed by stacking a plurality of battery cells. It is the purpose.

  A power supply device according to an aspect of the present invention includes a plurality of battery cells disposed along one direction, a plurality of separators disposed between adjacent battery cells, and expansion of the plurality of battery cells. A fastening portion for restraining. Each battery cell includes a flat rectangular parallelepiped outer can having a pair of wide surfaces and a sealing surface on which an output terminal is provided, and an electrode body having a flat surface facing the wide surface of the outer can. . Moreover, the adjacent battery cell is arrange | positioned with the attitude | position which opposes a mutual wide surface. Each separator includes an insulating part that insulates adjacent battery cells, and a pressing part that is stacked on the insulating part. Moreover, the press part is extended in the normal line direction of the sealing surface. The pressing part is formed so that the dimension in the normal direction of the sealing surface is smaller than the dimension of the outer can in the normal direction of the sealing surface and larger than the dimension of the flat surface in the normal direction of the sealing surface. In the normal direction, a flat surface is located between both ends of the pressing portion.

  According to the said structure, while insulating the adjacent battery cell, since the center part of the exterior can which is easy to expand | swell can be pressed, there exists an effect that the expansion | swelling of a battery cell can be suppressed efficiently.

It is a perspective view of the power supply device 1 in embodiment of this invention. FIG. 3 is a perspective view of the homogenous battery 2. 3 is a vertical longitudinal sectional view of the same battery 2. FIG. 2 is a vertical cross-sectional view of the same battery 2. FIG. FIG. 3 is a cross-sectional view for illustrating the structure of the current interrupt mechanism 7. It is sectional drawing which shows the mode of a diaphragm when the same electric current interruption mechanism 7 act | operates. It is sectional drawing which shows the shape of 3 A of separators in this invention. It is a top view which shows the shape of the separator 3A. It is sectional drawing which shows the shape of the separator 3B. It is sectional drawing which shows the shape of the separator 3C. It is sectional drawing which shows the shape of the separator 3D. It is a top view which shows the shape of the separator 3E. It is a top view which shows the shape of the separator 3F. It is sectional drawing of the separator 3 (3A) which integrally molded the insulation part and the press part. 3 is a graph showing the relationship between the pressing force when pressing using a flat separator and the cell width of the prismatic battery 2; It is a graph which shows the relationship between the pressing force at the time of pressing using the separator of embodiment of this invention, and the cell width of the square battery. It is sectional drawing which shows the shape of the separator in other embodiment.

  An embodiment of the present invention will be described in detail below with reference to FIGS.

  FIG. 1 is a perspective view of a power supply device 1 according to an embodiment of the present invention. As shown in FIG. 1, the power supply device 1 includes a battery block 4 formed by alternately stacking rectangular batteries 2 and insulating separators 3, and end plates 5 disposed at both ends of the battery block 4. A binding bar 6 is provided as a fastener that is installed on the end plate 5 and fastens the battery block 4 in a state of being pressed in the stacking direction.

  The rectangular batteries 2 constituting the battery block 4 are stacked such that the output terminals 21 are arranged on the upper surface of the battery block 4, and the adjacent rectangular batteries 2 are connected to each other via the bus bar 8. The prismatic batteries 2 are connected in series to increase the output voltage of the power supply device 1. The end plates 5 disposed at both ends of the battery block 4 have a rectangular parallelepiped shape whose outer shape is substantially equal to the outer shape of the rectangular battery 2, and are formed of a relatively high strength metal such as aluminum or aluminum alloy, a hard plastic, or the like. Has been. At the four corners of the end plate 5, screw holes for fixing a pair of bind bars 6 arranged vertically are fixed by screws, and the bind bars 6 can be installed.

  In addition, in the said embodiment, although each square battery 2 is connected in series, you may connect in parallel. By connecting the prismatic batteries 2 in parallel, the current capacity of the power supply device 1 can be increased. Further, the battery block 4 can also be configured by combining parallel connection or series connection according to the target output voltage or current capacity.

  2 to 4 are diagrams showing the configuration of the prismatic battery 2. As shown in FIG. 2 to FIG. 4, the prismatic battery 2 includes an outer can 22 formed in a flat rectangular parallelepiped shape with an upper surface open, a sealing body 23 that closes the opening of the outer can 22, and a sealing body 23. A battery cell having an output terminal 21 provided, for example, a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The outer can 22 is formed of a metal having excellent thermal conductivity, and improves the cooling performance of the prismatic battery 2. Examples of the metal having excellent thermal conductivity include aluminum and aluminum alloys. The outer can 22 has a wide surface 24 facing the separator 3, and the wide surface 24 is pressed by the separator 3 by being fastened by the bind bar 6. The wide surface 24 of the outer can 22 is composed of a ridge line portion 24 a located at the periphery of the wide surface 24 and a central portion 24 b located at the center. In the prismatic battery 2 having this configuration, when the internal pressure of the outer can 22 increases due to repeated charge and discharge, the central portion 24b of the outer can 22 particularly expands.

  As shown in the cross-sectional views of FIGS. 3 and 4, an electrode body 25 formed by winding a laminated body in which an insulating sheet 253 is interposed between a positive electrode 251 and a negative electrode 252 in the outer can 22, An electrolyte solution (not shown) is enclosed. The two output terminals 21 are electrically connected to the positive electrode 251 or the negative electrode 252 via the electrode current collecting member 26, respectively, and the current interrupting mechanism 7 is connected to the positive electrode 251 and the positive electrode 251. Between. The current interrupting mechanism 7 is configured to interrupt the current when the internal pressure of the battery cell, that is, the internal pressure of the outer can 22 becomes higher than the set pressure.

5 to 6 are cross-sectional views showing a specific configuration of the current interrupt mechanism 7. The current interruption mechanism 7 has a conduction portion 71 that electrically connects the output terminal 21 and the positive electrode 251, and is provided in the vicinity of the sealing body 23. The conduction portion 71 includes a connection metal 71 a that is electrically connected to the positive electrode 251, and a metal diaphragm 71 b that deforms according to the internal pressure of the outer can 22. The diaphragm 71b is electrically connected to the output terminal 21 and the diaphragm 71b by bringing the outer periphery into contact with the lower end of the output terminal 21 fixed to the sealing body 23 and welding the contact portion. The diaphragm 71b and the connection metal 71a are accommodated in an inner case 72 formed of an insulating material such as plastic.

  The inner case 72 hermetically seals the upper surface of the diaphragm 71b. By sealing the upper surface side of the diaphragm 71b in an airtight manner, the internal pressure of the outer can 22 does not act on the upper surface side of the diaphragm 71b. The inner pressure of the outer can 22 acts on the lower surface side of the diaphragm 71b, and a force that pushes the diaphragm 71b upward by the inner pressure acts. The force that pushes up the diaphragm 71b increases in proportion to the internal pressure of the outer can 22. When the internal pressure of the outer can 22 is sufficiently small, the force for pushing up the diaphragm 71b is also small, and the deformation of the diaphragm 71b is prevented by the sealed air on the upper surface side of the diaphragm 71b. When the internal pressure of the outer can 22 rises and the force for pushing up the diaphragm 71b exceeds a certain value, the diaphragm 71b cannot be prevented from being deformed and deformed as shown in FIG. The diaphragm 71b in the state of FIG. 6 is in a state of being separated from the connection metal 71a, and the output terminal 21 and the positive electrode 251 are electrically disconnected. The internal pressure at which the diaphragm 71b is deformed can be set according to the material thickness and shape of the diaphragm 71b. Since the deformed diaphragm 71b is held in this shape unless an external force is applied as shown in FIG. 6, once the current interrupting mechanism 7 is activated, the output terminal 21 and the positive electrode 251 are electrically disconnected thereafter. Maintained.

  With this configuration, when the internal pressure of the outer can 22 rises abnormally, the rectangular battery 2 can be electrically disconnected from a load to which the power supply device 1 is connected, such as a vehicle motor. In addition, in the said embodiment, although the electric current interruption mechanism 7 is provided in the positive electrode 251 side, it is good also as a structure provided in the negative electrode 252 side.

  7 to 13 are cross-sectional views for illustrating the shape of the separator 3. As shown in FIG. 7, a separator 3 is provided between adjacent rectangular batteries 2, and this separator 3 has an insulating portion 31 for insulating the adjacent rectangular batteries 2 and a wide width of the outer can 22. A pressing portion 32 is provided at a position facing the central portion 24 b of the surface 24. Specifically, the pressing portion 32 is formed at a position corresponding to the electrode body 25 enclosed in the outer can 22 and is configured to press a portion located below the current blocking mechanism 7 of the wide surface 24. It is preferable.

  When the end plate 5 is made of metal, the separator 3 is also disposed between the end plate 5 and the prismatic battery 2. The separator 3 disposed at the end of the battery block 4 has only one surface facing the rectangular battery 2, and the pressing portion 32 is also formed on the surface facing the rectangular battery 2. Further, the end separator 3 can be shaped to fit the end plate 5 so as to hold the end plate 5. By forming in this way, when the battery block 4 is fastened with the bind bar 6, the position shift of the end plate 5 can be prevented.

  In the separator 3 (3 </ b> A) shown in FIG. 7, the pressing portion 32 is formed in a shape protruding toward the wide surface 24 of the outer can 22 from the insulating portion 31. As shown in FIGS. 7 and 8, in the vicinity of the ridge line portion 24 a of the outer can 22, there is a step with respect to the pressing portion 32 so as to provide a gap between the insulating portion 31 and the ridge line portion 24 a of the outer can 22. Is provided. It is not always necessary to provide a gap between the insulating part 31 and the outer can 22, but a gap is provided at least between the ridge line part 24 a located in the vicinity of the sealing body 23 and the insulating part 31 of the separator 3 </ b> A. preferable.

As described above, in the outer can 22 of the rectangular battery 2, the central portion 24 b of the wide surface 24 is expanded, and the ridge line portion 24 a of the wide surface 24 is not expanded so much. In such a configuration, even if the ridge line portion 24a of the outer can 22 is pressed, a portion that hardly expands is pressed, so that the expansion of the outer can 22 cannot be efficiently suppressed. Further, the ridge line portion 24 a of the outer can 22, particularly the sealing body 23.
If an excessive force is applied to the ridge line portion 24a located in the vicinity, there is a possibility that the welded portion between the sealing body 23 and the outer can 22 may crack or the welding may be peeled off.

  In the above-described embodiment, when the binding bar 6 is fastened, the pressing portion 32 of the separator 3A is configured to mainly press the central portion of the wide surface 24 of the outer can 22, so that the change in expansion is large. The central portion 24b of the wide surface 24 can be pressed, and the expansion of the outer can 22 can be efficiently suppressed. In addition, in this configuration, since it is difficult to apply a load to the sealing body 23 and the like, it is possible to prevent the welded portion between the sealing body 23 and the outer can 22 from cracking or peeling off the weld, and thus safer. A power supply device can be provided.

  The separator 3 (3 </ b> B) shown in FIG. 9 is extended so that the insulating portion 31 protrudes upward from the end face of the outer can 22 near the sealing body 23. As described above, when the power supply device 1 is provided with a cooling mechanism, condensed water may adhere to the surface of the outer can 22 due to a temperature difference from the surroundings. In particular, when the outer can 22 is formed of a metal, the adhesion of the condensed water becomes remarkable. Since the separator 3B shown in FIG. 9 is configured such that the insulating portion 31 is located between the output terminals 21 of the adjacent rectangular batteries 2, for example, even if condensed water adheres to the outer can 22, The adjacent square batteries 2 do not come into contact with each other through water, and a short circuit between the adjacent square batteries 2 can be prevented. Therefore, the power supply device 1 including the separator 3B shown in FIG. 9 can prevent a short circuit due to condensed water by the insulating layer 31 while making the separator in a shape that can efficiently prevent the expansion of the rectangular battery 2.

  10 to 13 are for explaining the shape of the pressing portion 32 that presses the wide surface 24 of the outer can 22 more efficiently. In the separator 3 of FIGS. 10 to 13, the pressing portion 32 has a vertex portion 32 a located at the center and a peripheral portion 32 b located at the periphery, and is inclined gently from the vertex portion 32 a to the peripheral portion 32 b. A surface 33 is formed. According to this configuration, the contact area between the pressing portion 32 of the separator 3 and the wide surface 24 of the outer can 22 can be changed according to the force to be fastened. Specifically, when the outer can 22 is hardly expanded, the pressing portion 32 of the separator 3 is mainly in contact with the apex portion 32a and the wide surface 24, and when the outer can 22 is greatly expanded, The pressing part 32 is configured to press the wide surface 24 with the apex part 32a and the peripheral part 32b. At this time, the contact area between the pressing portion 32 and the wide surface 24 of the outer can 22 changes according to the gradient of the inclined surface 33. For example, when the pressing portion 32 is formed so that the slope of the inclined surface 33 becomes gentle, the contact area changes rapidly with respect to the change in fastening force. In addition, when the inclined surface 33 is formed to have a steep slope, the contact area between the pressing portion 32 and the wide surface 24 changes gradually with respect to the change in the fastening force.

  In the separator 3 (3C) of FIG. 10, the pressing part 32 is located on the first inclined surface 33a formed from the vertex part 32a to the peripheral edge part 32b located on the output terminal 21 side, and on the bottom face side from the vertex part 32a. And a second inclined surface 33b formed over the peripheral edge portion 32b. According to this configuration, as described above, the contact area between the pressing portion 32 and the wide surface 24 can be changed according to the gradient of the inclined surface 33, so that the peripheral portion 32b positioned on the output terminal 21 side and the bottom surface The load applied to the peripheral edge portion 32b located on the side can be reduced.

  In addition, as shown in FIG. 11, the inclined surface 33a and the inclined surface 33b can be formed so that the gradient is different between the inclined surface 33a and the inclined surface 33b. The separator 3 (3D) shown in FIG. 11 is formed so that the inclination of the second inclined surface 33b is gentler than that of the first inclined surface 33a. Unevenly change. In other words, the separator 3D shown in FIG. 11 is configured to mainly press the bottom surface side of the wide surface 24 of the outer can 22. According to this structure, the load concerning the sealing body 23 located in the output terminal 21 side of the armored can 22 can be reduced.

  Furthermore, in the said embodiment, since the electric current interruption mechanism 7 is provided in the sealing body 23 vicinity, the load concerning the electric current interruption mechanism 7 can be reduced. In particular, the current interrupt mechanism 7 described in the above embodiment has a configuration in which the diaphragm 71b is deformed according to the internal pressure of the outer can 22 and the electrical connection between the output terminal 21 and the electrode body 25 is interrupted. For example, when a pressing force such as a pressing portion pressing the outer can is applied to the diaphragm 71b, the diaphragm 71b may be deformed. Specifically, although the internal pressure of the outer can 22 is not so high, the diaphragm 71b is deformed and the current is interrupted or the electrical connection between the output terminal 21 and the electrode body 25 is interrupted. Due to the external force applied to the current interrupt mechanism 7, the diaphragm 71b may be deformed, and the output terminal 21 and the electrode body 25 may be connected again. According to the configuration of the separator 3D shown in FIG. 11, since the load applied to the current interrupt mechanism 7 can be reduced, an effect of preventing malfunction of the current interrupt mechanism 7 can be expected.

  In the separator 3 (3E) shown in FIG. 12, a third inclined surface 33c and a fourth inclined surface 33d are formed from the apex portion 32a to the peripheral edge portion 32b located on both the left and right sides, and a current blocking mechanism is formed. A slope located in the vicinity of 7 is a third slope 33c. The separator 3E shown in FIG. 12 is formed so that the third inclined surface 33c and the fourth inclined surface 33d have the same gradient. Since the separator 3E is formed symmetrically in the horizontal direction, the separator 3E can be configured to press the wide surface 24 of the outer can 22 evenly in the horizontal direction. As shown in FIG. 4 and the like, since the electrode body 25 is sealed in the outer can 22 with the axial direction of the electrode body 25 directed in the horizontal direction of the outer can 22, the outer can 22 is pressed evenly. By being configured in this way, it is possible to prevent a biased load from being applied to the electrode body 25 enclosed in the outer can 22.

  The separator 3 (3F) shown in FIG. 13 is formed such that the third inclined surface 33c is steeper than the fourth inclined surface 33d. As described above, the force for pressing the wide surface 24 of the outer can 22 can be biased by making the gradient of the inclined surface 33 different. In the embodiment shown in FIG. 13, the load on the current interrupting mechanism 7 can be further reduced by forming the third inclined surface 33 c located in the vicinity of the current interrupting mechanism 7 with a steep slope. .

  Although the separators 3 having various shapes are illustrated in FIGS. 10 to 13, they can be combined. In the embodiment shown in FIGS. 10 to 13, the separator 3 includes the insulating portion 31 and the pressing portion 32 as separate parts, but may be integrally molded as illustrated in FIG. 14. In this configuration, the insulating part 31 and the pressing part 32 are formed of an insulating material. As the insulating material, it is preferable to use an insulating resin having a relatively high strength. When the insulating part 31 and the pressing part 32 are configured to be integrally molded, the productivity of the separator 3 can be increased.

  Furthermore, in the said embodiment, the inclination of the inclined surface 33 (33a, 33b, 33c, 33d) does not necessarily need to be made into the inclination with a fixed inclination angle, and is continuously inclined as it leaves | separates from the vertex part 32a. In other words, the cross-sectional shape of the pressing portion 32 may be an arc shape.

Further, in the separator 3 shown in FIGS. 8 to 14, the portion facing the peripheral edge 24 a of the insulating portion 31 is formed on a flat surface parallel to the wide surface 24, as illustrated in FIG. 17. The portion of the insulating portion 31 that faces the peripheral edge portion 24 a may be inclined along the inclined surface 33 of the pressing portion 32. From the viewpoint of productivity and cost, the separator 3 may be integrally formed with the insulating portion 31 and the pressing portion 32 using an insulating resin as shown in FIG. If this becomes complicated, the mold for molding the separator 3 also becomes complicated, which may increase the cost. According to the above-described configuration, the portion facing the peripheral edge 24a of the insulating portion 31 has a shape that is inclined along the inclined surface 33 of the pressing portion 32. Therefore, the shape of the separator 3 is relatively simple, and the cost is reduced. Can be suppressed.

  Here, the shape of the separator 3 and the change of the fastening force by the bind bar 6 will be described in detail. Specifically, regarding the relationship between the pressing force and the cell width when pressing the outer can 22 with a separator, a comparison between a generally known flat plate separator and the separator 3D in the embodiment shown in FIG. I do.

  15 to 16 are graphs showing the results of the simulation performed by the inventor of the present invention. The shape of the outer can 22 when expanded and the strength against deformation of the outer can 22 are input to simulate the deformation of the rigid body. It is what you did. Strictly speaking, the shape of the outer can 22 is such that the wide surface 24 widens as it approaches the upper surface opening closed by the sealing body 23 so that the electrode body 25 can be easily inserted from the opening portion of the outer can 22. Tilted. Because of this shape, the width dimension of the outer can 22 differs between the sealing body side and the bottom surface side, but in the following description, the width dimension of the central portion of the outer can 22 is defined as the cell width.

  FIG. 15 is a graph showing the relationship between the cell width and the pressing force F (fastening force of the bind bar 6 in the above embodiment) when the square battery 2 is pressed with a general flat plate separator. Specifically, the rectangular battery 2 in which the outer can 22 having a width of 27 mm is expanded to about 28.5 mm has been verified, and the vertical axis represents the pressing force and the horizontal axis represents the cell width. As is clear from FIG. 15, when the outer can 22 is pressed by the separator so as to reduce the cell width from the original dimension (27 mm in FIG. 15), the necessary pressing force rapidly increases.

  The expanded outer can 22 is mainly shaped so that the wide surface 24 of the outer can 22 bulges. When the expanded outer can 22 is pressed, only a part of the outer can 22 bulging is separated by the separator. Pressed. On the other hand, the outer can 22 of the prismatic battery 2 pressed to the original size has the same shape as or substantially the same shape as the outer shape of the unexpanded outer can 22. Therefore, when the outer can 22 in this state is further pressed to reduce the cell width, the contact area between the separator and the outer can 22 is changed as compared with the case where only the bulging part of the outer can 22 is pressed. In addition, the pressing force required to reduce the size of the outer can 22 increases rapidly.

  In addition, as described above, since the wide surface 24 is inclined so as to spread toward the sealing body 23 side, the outer can 22 of the rectangular battery 2 pressed to the original size is further flattened. In the case of pressing with the separator, the flat separator contacts the ridge line portion 24a on the sealing body 23 side of the outer can 22. Since the contact portion corresponds to a portion that is difficult to deform the outer can 22 in the vicinity of the ridge line portion 24a of the outer can 22, the outer can 22 is further removed from the state where the separator and the ridge line portion 24 a of the outer can 22 are in contact. When the size is reduced, the required pressing force increases rapidly.

  FIG. 16 is a graph showing the relationship between the cell width and the pressing force F when the prismatic battery 2 is pressed by the separator 3D in the embodiment. Specifically, as in FIG. 15, a rectangular battery in which an outer can 22 having a width of 27 mm is expanded to about 28.5 mm has been verified. Yes. As shown in FIG. 16, when pressing the outer can 22 expanded by the separator 3D of the above-described embodiment, the cell width is 27 mm (original) unlike the result of FIG. 15 using a general separator. The pressing force does not change abruptly even if it is in a state of being reduced more than (dimension). This is because by making the shape of the separator like the separator 3D, even if the cell width changes, the area where the outer can 22 and the separator 3D come into contact with each other can be changed little.

As described above, since the separator 3 has a gap between the ridge line portion 24 a and the insulating portion 31, the vicinity of the ridge line portion 24 a is configured not to contact the separator 3 regardless of the cell width of the outer can 22. be able to. In addition, by providing the pressing portion 32 with an inclined surface, the contact area between the separator 3 and the wide surface 24 of the outer can 22 can be configured to change gently.

  On the other hand, the dimensions of the outer can vary during manufacturing, and this dimensional error cannot be completely eliminated. When a dimensional error occurs in the outer can 22, the relationship between the cell width of the outer can 22 and the pressing force F corresponds to the parallel translation of the graph in FIGS. 15 and 16. Illustratively, the dimensional error of the outer can 22 is on the order of about 0.1 mm with respect to the outer can 22 of 27 mm. In the power supply device 1 of the above embodiment, when the prismatic battery 2 is not restrained, various problems such as dropping of the stacked prismatic battery 2 and an increase in load on the bus bar 8 occur. Therefore, in the power supply device 1 as in the above-described embodiment, the state in which the square battery 2 is not restrained must be avoided, and the bind bar 6 has an optimum value when there is no error (in FIG. 15 and FIG. It is necessary to configure so that it can be restrained with a force slightly larger than the pressing force required when the width is 27 mm.

  As described above, when pressing the outer can 22 with a flat separator, the pressing force F changes greatly according to the cell width of the outer can 22, and therefore, it is easily affected by the dimensional error of the outer can 22. On the other hand, in the configuration of the separator 3 of the above-described embodiment, the pressing force F does not change abruptly. Therefore, the influence due to the dimensional tolerance of the stacked rectangular batteries 2 is pressed by a general flat plate separator. It can be reduced compared to the configuration. Therefore, it is possible to reduce the variation in the load applied to the bind bar 6, so there is no need to increase the rigidity of the bind bar 6 more than necessary. For example, the thickness of the bind bar 6 is reduced to make the power supply device 1 small. It can also be converted.

  Thus, the battery block 4 is formed by alternately stacking the rectangular battery 2 having the rectangular parallelepiped outer can 22 and the separator 3 having the pressing portion 32. After the end plates 5 are disposed at both ends of the battery block 4 in the stacking direction, the bind bars 6 are installed on the end plates 5. Specifically, the battery block 4 is pressed in the stacking direction using a jig, and the bind bar 6 is fixed to the end plate 5 with screws. Thus, the battery block 4 on which the bind bar 6 is installed is fastened in a state of being pressed by the bind bar 6 in the stacking direction even when the jig is removed. As for the fastened battery block 4, the dimensions of the battery block 4 are restricted, and the fastening force changes according to the state of expansion of the rectangular battery 2 constituting the battery block 4.

  The above power supply device 1 can be used as an in-vehicle power supply. Vehicles equipped with a power supply device include electric vehicles such as hybrid vehicles and plug-in hybrid vehicles that run only with an engine and a motor, or electric vehicles that run only with a motor, and are used as a power source for these vehicles.

  In addition to power supplies for vehicles, backup power supplies that can be mounted on racks of computer servers, backup power supplies for wireless base stations such as mobile phones, power supplies for home and factory storage, street light It can also be used as appropriate for applications such as a power source, a power storage device combined with a solar cell, a backup power source such as a traffic light.

  The present invention is widely applicable to power supply devices.

DESCRIPTION OF SYMBOLS 1 Power supply device, 2 square battery, 21 output terminal, 22 exterior can, 23 sealing body, 24 wide surface, 24a ridgeline part, 24b center part, 25 electrode body, 251 positive electrode, 252 negative electrode, 253 insulating sheet, 26 electrode current collection Member, 3 Separator, 31 Insulating part, 32 Pressing part, 32a Vertex part, 32b Peripheral part, 33 Inclined surface, 33a First inclined surface, 33b
2nd inclined surface, 33c 3rd inclined surface, 33d 4th inclined surface, 4 battery block, 5
End plate, 6 Bind bar, 7 Current interrupt mechanism, 71 Conducting part, 71a Connection metal, 71b Diaphragm, 72 Inner case, 8 Bus bar

Claims (5)

A plurality of battery cells arranged along one direction, each battery cell having a flat rectangular parallelepiped can having a pair of wide surfaces and a sealing surface provided with an output terminal; An electrode body having a flat surface facing the wide surface, and the adjacent battery cells are arranged in a posture in which the wide surfaces face each other, and the plurality of battery cells,
Each of which is a plurality of separators disposed between adjacent battery cells, each of which includes an insulating portion that insulates adjacent battery cells, and a pressing portion that is stacked on the insulating portion. The plurality of separators, wherein the pressing portion extends in the normal direction of the sealing surface;
A fastening portion for suppressing expansion of the plurality of battery cells, the fastener comprising fastening the plurality of battery cells and the plurality of separators;
The pressing portion has a dimension in the normal direction of the sealing surface that is smaller than the dimension of the outer can in the normal direction of the sealing surface, and is smaller than the dimension of the flat surface in the normal direction of the sealing surface. A power supply device, wherein the flat surface is located between both ends of the pressing portion in the normal direction of the sealing surface. The power supply device according to claim 1,
In each of the separators, the pressing portion and the insulating portion overlap each other in a region corresponding to a central region of the wide surface in the normal direction of the wide surface of the adjacent battery cell. The power supply device according to claim 1 or 2,
The power supply device, wherein the pressing portion and the insulating portion are separate bodies. The power supply device according to any one of claims 1 to 3,
Each battery cell has a safety element including a deformed metal that deforms according to the internal pressure in the corresponding outer can,
The power supply device according to claim 1, wherein the pressing portion has an end portion in a normal direction of the sealing surface located closer to a center portion of the wide surface than a position where the deformed metal is provided. The power supply device according to claim 4,
The deformable metal includes a dome portion formed in a convex shape protruding downward.

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