JP5552391B2 - Square secondary battery - Google Patents

Description

  The present invention relates to a prismatic secondary battery having a structure in which a power generation element group is supported by a lid.

  The structure of a secondary battery for driving a vehicle includes a sheet for both positive and negative electrodes, a separator for insulation between the positive and negative electrode plates, and an electrolyte solution in a sealed square container made of metal or resin. A device provided with an external terminal that is housed and connected to both electrodes of the power generation element group is widely known.

  In a conventional prismatic secondary battery, a power generation element group is mechanically suspended by a battery lid via positive and negative electrode plates, and the positive and negative electrode plates are electrically insulated from the battery lid. (For example, patent document 1).

JP 2001-30475 A

  In a conventional prismatic secondary battery, a power generation element group vibrates like a swing with a battery lid and a positive / negative electrode plate joint as a fulcrum by external vibration. As a result, the life of the secondary battery may be affected.

(1) A prismatic secondary battery according to the invention of claim 1 is a power generation element formed by winding a battery sheet including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode around a power generation element core. A flat rectangular parallelepiped battery can for housing the power generation element group, a battery lid for sealing the opening of the battery can, and a suspension member for suspending the power generation element group on the battery lid The power generation element core is provided with a core extension portion protruding toward the inner surface facing the battery can, and the core extension portion is in contact with the inner surface.
(2) The prismatic secondary battery according to the invention of claim 2 is a power generation in which a battery sheet including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode is wound around a power generation element core. An element group, a flat rectangular battery can for housing the power generation element group, a battery lid for sealing an opening of the battery can, and a suspension member for suspending the power generation element group on the battery lid The power generating element core is provided with a core extension that protrudes toward the opposing inner surface of the battery can, and the inner surface is provided with a guide that engages with the core extension. It is characterized by .

  According to the present invention, there is no possibility that vibrations acting on the secondary battery affect the battery life.

1 is a perspective view showing a first embodiment of a prismatic secondary battery according to the present invention. FIG. The perspective view which shows the positive electrode for the electric power generation element group in FIG. The perspective view which shows the negative electrode for the electric power generation element groups in FIG. The perspective view which shows the battery sheet for the electric power generation element groups in FIG. The perspective view which shows the electric power generation element core for the electric power generation element group in FIG. The disassembled perspective view which shows the electric power generation element group in FIG. The perspective view which shows the connection state of the electric power generation element group in FIG. 1, and a positive / negative electrode connection board. The perspective view which shows the internal structure of a battery which connected the battery cover to the structure of FIG. The perspective view which shows the battery can and guide in 2nd Embodiment of the square secondary battery by this invention. The perspective view which shows the electric power generation element core of 2nd Embodiment. The top view which shows the battery can and guide in 3rd Embodiment of the square secondary battery by this invention. The perspective view which shows the electric power generation element core of 3rd Embodiment. The top view which shows the guide in 4th Embodiment of the square secondary battery by this invention. The cross-sectional view which shows the battery can and guide in 4th Embodiment. The perspective view which shows 5th Embodiment of the square secondary battery by this invention.

  An embodiment of a prismatic secondary battery according to the present invention will be described with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, the rectangular secondary battery has a flat rectangular battery can 19 having an opening 19M at one end, a power generation element group 10 accommodated in the battery can 19, and an opening 19M sealed. And a battery lid 14 to be provided. The battery can 19 forms a flat rectangular container by a bottom surface 19Rm facing the opening 19M, a pair of wide surfaces 19RM facing the front and back, and a pair of narrow surfaces 19S facing left and right.

  The power generation element group 10 includes a power generation element core 8 having a winding axis parallel to the bottom surface 19Rm and the wide surface 19RM of the battery can 19, and positive and negative electrodes 1a and 4a wound around the outer periphery thereof (FIGS. 2 and 3). ). The power generation element group 10 has a flat shape corresponding to the battery can 19 with a wound thickness being compressed.

  Positive and negative electrode plates 11 and 12 are welded to the power generation element group 10 at a welded portion 13, and the positive and negative electrode plates 11 and 12 are attached to the battery lid 14 via an electrical insulator 15. A positive electrode terminal 17 is inserted into the positive electrode plate 11 and the electrical insulator 15, a negative electrode terminal 18 is inserted into the negative electrode plate 12 and the electrical insulator 15, and the positive and negative electrode terminals 17 and 18 are The battery lid 14 is fastened by a nut 16 via an electrical insulator 15 from both sides.

  In the secondary battery adopting such a configuration, the power generation element group 10 is mechanically suspended by the battery lid 14 via the positive and negative electrode plates 11 and 12, and the positive and negative electrode plates 11 and 12 are batteries. It is electrically insulated from the lid 14.

  The power generation element core 8 is provided with core extensions 9 at both ends in the winding axis direction, and each core extension 9 is in close contact with the inner surfaces of the left and right side surfaces 19S. Thereby, the vibration of the power generation element group 10 is suppressed.

[Production method]
The square secondary battery of this embodiment is manufactured by the following steps.

[Positive electrode formation process]
As shown in FIG. 2, first, an active material 2 is applied to a part of both surfaces of a positive electrode material 1 of an aluminum thin film to form a positive electrode 1 a, and an uncoated region is defined as a positive electrode active material uncoated region 3. To do.
FIG. 2 is a view for explaining the structure of the positive electrode 1a, and the positive electrode 1a is formed as a long sheet.

[Negative electrode forming step]
As shown in FIG. 3, an active material 5 is applied to a negative electrode material 4 of a copper thin film to form a negative electrode 4 a, and an uncoated region is defined as a negative electrode active material uncoated region 6.
FIG. 3 is a view for explaining the structure of the negative electrode 4a, and the negative electrode 4a is formed as a long sheet.

[Battery sheet creation process]
As shown in FIG. 4, the battery sheet 23 is produced by sandwiching the positive electrode 1a and the negative electrode 4a between separators 7. FIG. 4 is also a view for explaining the structure of the battery sheet 23 as in FIGS. 2 and 3, and the battery sheet 23 is formed as a long sheet. The symbol W in FIG. 4 represents the width of the battery sheet 23, and the battery sheet 23 is a long sheet having a width W. The width W is a dimension shorter than the width of the wide surface 19RM of the battery can 19, in other words, the distance between the side surfaces 19S.

[Power generation element group creation process]
As shown in FIG. 5, the power generating element core 8 is configured by forming a flat plate made of an insulating material into a letter shape. The power generating element core 8 includes a short piece portion 8A having a length L that extends in the winding axis direction substantially equal to the width W (FIG. 4) of the battery sheet 23, and a long piece portion 8B opposite to the short piece portion 8A. The short piece portion 8A and the long piece portion 8B are connected by a connecting portion 8C that is narrower than the length of the short piece portion 8A, and the core extension portions 9 are provided at both ends of the long piece portion 8B.

  As shown in FIG. 6, the power generation element group 10 is manufactured by winding the battery sheet 23 around the core 8 so as to go around the short piece portion 8 </ b> A and the long piece portion 8 </ b> B of the power generation element core 8. Each core extension 9 protrudes from the end surface of the battery sheet 23 in the left-right direction of the winding axis. The length of the long piece portion 8B is formed to be equal to the dimension between the left and right side surfaces 19S of the battery can 19. Therefore, when the power generation element group 10 is housed in the battery can 19, the length of the long piece portion 8 </ b> B is set so that both end surfaces of the core extension portion 9 are in close contact with the inner surfaces of the left and right side surfaces 19 </ b> S.

[Battery structure formation process]
As shown in FIG. 7, the positive electrode active material uncoated region 3, the negative electrode active material uncoated region 6, the positive electrode plate 11, and the negative electrode plate 12 of the power generation element group 10 are welded at a weld connection 13 by ultrasonic welding. .

  Further, as shown in FIG. 8, the positive electrode plate 11 and the positive electrode terminal 17 are connected to each other, and the negative electrode plate 12 and the negative electrode terminal 18 are connected to each other by a nut 16 with an electric insulator 15 interposed therebetween. The electrode plates 11 and 12 are fixed to the battery lid 14. Thereby, the battery internal structure 24 in which the power generation element group 10 is suspended by the battery lid 14 is formed.

[Secondary battery completion process]
The power generation element group 10 is accommodated in the battery can 19 through the opening 19M. At this time, the power generation element group 10 is inserted toward the bottom surface 19Rm while the end surface of the core extension 9 is in contact with the inner surface of the side surface 19S. The opening 19M is sealed by welding the battery lid 14 to the battery can 19 by laser beam welding. An electrolytic solution (not shown) is injected into the battery can 19 from the injection port. The injection port is then sealed.

  The vibration of the power generation element group 10 occurs because there is a gap between the power generation element group 10 and the battery can 19, and the core extension portion 9 extending to the left and right is formed on the inner surfaces of the left and right side surfaces 19 </ b> S of the battery can 19. Since they are in close contact, vibration of the power generation element group 10 in the wide direction of the battery can 19 can be suppressed.

  The vibration in the battery can depth direction along the side surface 19S is suppressed by friction between the end surface of the core extension 9 and the inner surface of the side surface 19S.

  Further, since the core 8 is made of an insulating material, the core 8 is insulated from the battery sheet 23. Even when the battery can 19 made of a metal material has a positive or negative potential, the battery can 19 and the core 8 are insulated, so there is no electrical problem.

[Second Embodiment]
A second embodiment of the prismatic secondary battery according to the present invention will be described with reference to FIG. In the figure, the same or corresponding parts as those in the first embodiment are designated by the same reference numerals, and the differences will be mainly described.

  In the second embodiment, in addition to the configuration of the first embodiment, a guide 20 for supporting the core extension 9 is provided. The material of the guide 20 may be an insulating material or a conductive material. However, when the core 8 is manufactured from a conductive material, the guide 20 needs to be manufactured from an insulating material. In this case, the metal core 8 is insulated by the positive electrode members 1a and 4a.

  As shown in FIG. 9, a guide 20 is inserted into the battery can 19 of the square secondary battery over the substantially entire length of the side surface 19 </ b> S inside the side surface 19 </ b> S. The guide 20 is formed with a groove 25 extending substantially in the center in the width direction of the side surface 19S and extending in a direction perpendicular to the bottom surface 19Rm, and the core extension 9 is inserted into the groove 25.

  The groove 25 has a rectangular cross section, and both ends thereof are open. Thereby, the core extension part 9 can be inserted from the opening part 19M side, and the assembly of the battery internal structure 24 is easy.

  The core extension portion 9 is in close contact with the bottom surface 25B of the groove 25, and the vibration is suppressed in the direction orthogonal to the side surface 19S, as in the first embodiment. Further, the groove 25 suppresses the vibration of the core extension 9 also in the battery can depth direction perpendicular to the wide surface 19RM.

  Since the vibration of the power generation element group 10 and the battery internal structure 24 is suppressed by engaging the core extension 9 with the groove 25, the minimum extension length of the guide 20, that is, the groove 25 is set to the core extension 9. May be the range in which the core extension portion 9 is in the depth direction of the battery can. In the second embodiment, as shown in FIG. 9, the guide 20 does not extend to the bottom of the battery can 19, that is, the bottom surface 19 </ b> Rm.

  However, as shown in FIG. 9, when the guide 20 is extended to the opening 19 </ b> M, workability when the battery internal structure 24 is accommodated in the battery can 19 is good.

[Third Embodiment]
A third embodiment of the prismatic secondary battery according to the present invention will be described with reference to FIGS. In the figure, the same or corresponding parts as those in the first embodiment are designated by the same reference numerals, and the differences will be mainly described.

  In the third embodiment, the groove having a rectangular cross section in the second embodiment has a T-shaped cross section, and the core extension portion 9 has a T-shaped shape.

  As shown in FIG. 12, the power generating element core 8 is formed by connecting a pair of long piece portions 8B with a connecting portion 8C, and a T-shaped core extension portion 9T is provided at the tip of each long piece portion 8B. It has been.

  As shown in FIG. 11, a guide 21 is inserted into the battery can 19 inside the side surface 19S. The guide 21 is formed with a groove 28 extending substantially in the center in the width direction of the side surface 19S and extending in a direction perpendicular to the bottom surface 19Rm, and the core extension 9T is fitted into the groove 28. The groove 28 has a T-shaped cross section.

  By fitting the groove 28 having a T-shaped cross section with the T-shaped core extension 9T, the power generation element group 10 is suppressed from vibrating in a direction perpendicular to the side surface 19S. Moreover, the groove | channel 28 suppresses the vibration of the core extension part 9 also about the battery can depth direction orthogonal to the wide surface 19RM.

As in the second embodiment, the groove 28 has an open end on the opening 19M side, and the core extension 9T can be inserted from the opening 19M side. Therefore, assembly of the battery internal structure 24 is easy.
In the third embodiment, in addition to the effect of the second embodiment, the effect of improving the vibration suppression effect in the direction orthogonal to the side surface 19S is obtained.

[Fourth Embodiment]
A square secondary battery according to a fourth embodiment of the present invention will be described with reference to FIGS. In the figure, the same or corresponding parts as those in the first embodiment are designated by the same reference numerals, and the differences will be mainly described.

  The fourth embodiment uses a guide 26 provided with a hole 27 into which an end of the core extension 9 is inserted, instead of the guide 20 provided with the groove 25 of the second embodiment.

  As shown in FIGS. 13 and 14, a guide 26 is inserted inside the side surface 19 </ b> S over substantially the entire length of the side surface 19 </ b> S. In the guide 26, a hole (or recess) 27 having a cross section corresponding to the cross section of the core extension 9 is formed at approximately the center in the width direction of the side surface 19S.

  The core extension 9 of the power generation element core 8 is inserted into the hole 27, and the power generation element group 10 is restrained in all directions along the side surface 19S. Further, the core extension portion 9 is in contact with the bottom surface 27B of the hole 27, and the power generating element group 10 is also restrained in the direction orthogonal to the side surface 19S.

  As a result, the power generation element group 10 is suppressed from vibrating in all directions.

  When assembling, before accommodating the power generation element group 10 in the battery can 19, the core extension 9 protruding from both end faces of the power generation element group 10 is engaged with the guide 26, and then the guide 26 is attached to the side surface 19 </ b> S. The power generation element group 10 can be accommodated in the battery can 19 by sliding along the inner surface.

  In the fourth embodiment, in addition to the effect of the second embodiment, the effect of improving the vibration suppressing effect in the direction orthogonal to the bottom surface 19Rm is obtained.

[Fifth Embodiment]
A fifth embodiment of the prismatic secondary battery according to the present invention will be described with reference to FIG. In the figure, the same or corresponding parts as those in the first embodiment are designated by the same reference numerals, and the differences will be mainly described.

  In the fifth embodiment, in addition to the configuration of the first embodiment, the power generation element group 10 is provided with an anti-vibration film 22 that contacts the inner surface of the wide surface 19RM of the battery can 19. Since the surface of the power generation element group 10 is covered with the separator, the vibration stopper fill 22 may be adhered to the surface of the separator.

  As shown in FIG. 15, the vibration generating film 22 is affixed to the power generation element group 10 on the surface facing the wide surface 19RM in the vicinity of the ultrasonic weld 13. The vibration stop film 22 is in close contact with the inner surface of the wide surface 19RM, and there is no gap between the power generation element group 10 and the wide surface 19RM, and vibration in a direction perpendicular to the wide surface 19RM is suppressed.

  That is, the fifth embodiment has an effect that the vibration suppressing effect in the direction orthogonal to the wide surface 19RM is high in addition to the effect of the first embodiment.

  The position of the vibration stop film 22 can be arranged at any position that fills the gap between the power generation element group 10 and the wide surface 19RM. Since the ultrasonic welded portion 13 is the point of action of the load (power generation element group 10) on the positive and negative electrode plates 11, 12, the vibration preventing film 22 is most affixed to a location close to the ultrasonic welded portion 13. Vibration can be effectively suppressed.

[Modification]
(1) In 1st Embodiment, the end surface of the core extension part 9 was stuck to the inner surface of the side surface 19S, and the vibration of the electric power generation element group 10 was suppressed. However, the end surface of the core extension 9 may be bonded to the inner surface of the side surface 19S. That is, the core extension 9 may be fixed to the inner surface of the side surface 19S. By fixing the core extension 9, vibration is strongly suppressed in the direction along the side surface 19 </ b> S, and the vibration suppression effect is enhanced in the direction orthogonal to the side surface 19 </ b> S.

(2) In the first embodiment, the power generation element core 8 is provided with one long piece portion 8B, and the core extension portions 9 are provided at both ends of the long piece portion 8B. However, instead of the short piece portion 8A, a long piece portion is provided. 8B may be adopted and the core extension portions 9 may be provided at both ends of both long piece portions 8B. Thereby, the vibration suppressing effect is improved.

(3) In the second embodiment, the guide 20 is set to a length that does not contact the bottom surface 19Rm, but may be a length that contacts the bottom surface 19Rm.

(4) When applying the modification which provides two long piece parts 8B in 4th Embodiment, if the two holes 27 are provided in the guide 26, a vibration suppression effect will improve further.

(5) In the fifth embodiment, the vibration is prevented by both the core extension portion 8B of the power generation element core 8 and the vibration stop film 22, but the core extension portion 9 is omitted and only the vibration stop film 22 is used to generate the power generation element. It is also possible to suppress the vibration of the group 10. In this case, it is effective to cover the surface of the vibration stop film 22 with a material having a high friction coefficient.

  The above description is an example, and the present invention is not limited to the embodiment and the modification. Therefore, the shape and structure of the positive and negative electrode plates 11 and 12 that suspend the power generation element group 10 on the lid 14 are not limited to the embodiment. The shape and structure of the positive and negative electrode terminals 17 and 18 are not limited to the embodiment.

  You may combine the above embodiment and modification suitably.

  The present invention can also be applied to a secondary battery in which the power generation element group 10 is not directly inserted into the battery can 19 and the inner surface of the battery can 19 is covered with a bag-like insulating case. In the first embodiment, the end surface of the core extension 9 is in contact with the inner surface of the battery can 19 via the insulating case. In the second, third, and fourth embodiments, the guides 20, 21, and 26 may be made of an insulating material, and an opening and a hole through which the core extension portion is inserted may be formed in a part of the insulating case.

1: positive electrode material 1a: positive electrode 2, 5: active material 3: positive electrode active material uncoated region 4: negative electrode material 4a: negative electrode 6: negative electrode active material uncoated region 7: separator 8: power generating element core 8A: short piece 8B: Long piece portion 8C: Connection portion 9, 9T: Core extension portion 10: Power generation element group 11: Positive electrode plate 12: Negative electrode plate 13: Ultrasonic welding portion 14: Battery lid 15: Electrical insulator 16: Nut 17 : Positive electrode terminal 18: Negative electrode terminal 19: Battery can 19M: Opening 19Rm: Bottom surface 19RM: Wide surface 19S: Side surfaces 20, 21, 26: Guide 22: Vibration stopper film 23: Battery sheet 24: Battery internal structure 25, 28: Groove 25B: Bottom 27: Hole (or recess)
27B: Bottom

Claims (6)

A power generation element group formed by winding a battery sheet including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode around a power generation element core;
A flat rectangular parallelepiped battery can for housing the power generation element group;
A battery lid for sealing the opening of the battery can;
A suspension member for suspending the power generation element group on the battery lid,
The prismatic secondary battery according to claim 1, wherein the power generating element core is provided with a core extension portion protruding toward an inner surface facing the battery can, and the core extension portion is in contact with the inner surface. A power generation element group formed by winding a battery sheet including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode around a power generation element core;
A flat rectangular parallelepiped battery can for housing the power generation element group;
A battery lid for sealing the opening of the battery can;
A suspension member for suspending the power generation element group on the battery lid,
The power generation element core is provided with a core extension portion that protrudes toward the inner surface facing the battery can, and the inner surface is provided with a guide that engages with the core extension portion. Square secondary battery. The prismatic secondary battery according to claim 2,
The guide has a groove extending in a direction orthogonal to the bottom surface of the battery can, and the core extension is engaged with the groove. The prismatic secondary battery according to claim 3,
2. The square secondary battery according to claim 1, wherein the groove is T-shaped, and the core extension is formed in a shape complementary to the T-shape. The prismatic secondary battery according to claim 2,
A square secondary battery, wherein a hole is formed in the guide, and the core extension is engaged with the hole. The prismatic secondary battery according to claim 1,
A prismatic secondary battery, wherein a vibration preventing film is provided on a surface of the power generation element group to fill a gap between the inner surface of the battery can and the surface.

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