JP5930162B2 - battery - Google Patents

Description

  The present invention relates to a structure of a battery mounted on a vehicle such as an automobile.

  Conventionally, for example, non-aqueous electrolyte secondary batteries represented by nickel metal hydride secondary batteries and lithium ion secondary batteries are known as secondary batteries for relatively small electronic devices such as mobile phones and personal computers. Yes. In recent years, development of large-sized batteries mounted on various vehicles such as electric vehicles has been progressing.

  As a structure of such a battery, for example, an electrode group (electrode bundle) laminated by winding a positive electrode plate and a negative electrode plate through a separator is formed into a rectangular exterior member (case) together with a non-aqueous electrolyte. Some are housed inside and the exterior member is sealed with a lid member (for example, Patent Document 1).

  The positive electrode plate and the negative electrode plate are respectively connected to one end side of the current collector at the axial end of the electrode group, and the other end side of the current collector is connected to a terminal portion provided on the lid member. For example, in the configuration described in Patent Document 1, the positive electrode plate and the negative electrode plate are connected to the positive electrode terminal and the negative electrode terminal corresponding to the terminal portion by the positive electrode lead and the negative electrode lead corresponding to the current collector. The positive electrode lead and the negative electrode lead have a connection plate connected to the terminal portion and a strip-shaped current collector extending downward from the connection plate, and the current collector is connected to the positive electrode plate or the negative electrode plate. Has been. And this current collection part is extended toward the downward direction from the connection plate so that it may become substantially parallel to the surface of an electrode group.

  As described in Patent Document 1, the strip-shaped current collector (lead) is extended from a connection plate (connection) so as to be substantially parallel to the surface of the electrode group (electrode bundle). Yes.

JP 2011-71109 A JP 2002-298906 A

  By the way, when such a battery is mounted in a vehicle, there is a possibility that a large impact is applied to the battery from the outside, for example, when the vehicle collides. In the configuration in which the lead portion extends substantially parallel to the surface of the electrode bundle as described above, when an impact is applied to the battery from the outside of the lead portion, the lead portion is deformed inward and enters the electrode bundle. There is a possibility that an internal short circuit may occur due to contact with the positive electrode plate or the negative electrode plate.

  In the secondary battery having a structure in which the positive electrode current collector plate is welded to the end portion of the positive electrode protruding from the electrode bundle, at least the outermost peripheral portion of the positive electrode end portion (lead welding end portion) protruding from the electrode bundle There is one in which the angle is inclined to the inner peripheral side (see Patent Document 2).

  In this configuration, it is possible to suppress the occurrence of an internal short circuit due to the end of the positive electrode coming into contact with the inner wall of the container that also serves as the negative electrode terminal. However, the configuration described in Patent Document 2 does not suppress an internal short circuit accompanying the deformation of the current collector.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a battery capable of suppressing entry of the lead portion into the electrode bundle even when the lead portion is deformed by an external impact. And

A first aspect of the present invention that solves the above problem is that a positive electrode plate and a negative electrode plate are offset laminated via a separator to form a laminate, and one of the wound bodies formed by winding the laminate An electrode bundle having an end surface as a positive electrode surface and the other end surface as a negative electrode surface, a plurality of lead portions arranged corresponding to each of the positive electrode surface and the negative electrode surface of the electrode bundle, and connected to the positive electrode surface; A plurality of lead portions connected to the negative electrode surface; and a rectangular exterior member that accommodates the electrode bundle and the lead portion; and the lead portion includes the exterior member and the positive electrode surface or the negative electrode. An inclined portion arranged to be inclined with respect to the positive electrode surface or the negative electrode surface, and a flat portion arranged in parallel to the positive electrode surface or the negative electrode surface. The plurality of lead portions to be connected are inclined between the inclined portions. The direction is the same and the inclination with respect to the positive electrode surface is substantially the same, and the plurality of lead parts connected to the negative electrode surface have the same inclination direction between the inclined portions and the inclination with respect to the negative electrode surface, respectively. The battery is characterized by being substantially identical.

In the first aspect, when an impact (external force) is applied from the side of the exterior member, the lead portion moves (deforms) to the electrode bundle side while the inclined portion rotates. As a result, the lead portion is substantially in surface contact with the end face of the electrode bundle, and movement of the lead portion toward the electrode bundle is restricted. Further, as the space required for the lead portion is reduced, the electrode bundle can be increased, and the battery capacity per unit volume is improved. Moreover, when joining each lead part and a positive electrode plate or a negative electrode plate by welding etc., since both joint parts can be accessed from the same direction, workability | operativity improves.

According to a second aspect of the present invention, in the battery of the first aspect, the entire portion of the lead portion that overlaps the positive electrode surface or the negative electrode surface is the inclined portion.

In the second aspect, the deformation of the lead portion is more reliably suppressed.

  According to the present invention, even when the lead portion of the current collector is deformed by an external impact, the lead portion can be prevented from entering the electrode bundle. Therefore, it is possible to suppress the occurrence of an internal short circuit due to the current collector contacting the positive electrode plate or the negative electrode plate.

It is a disassembled perspective view which shows schematic structure of the sealed battery which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view which shows schematic structure of the sealed battery which concerns on one Embodiment of this invention. It is the schematic which shows the laminated structure of the electrode bundle which concerns on one Embodiment of this invention. 1 is a cross-sectional view showing a schematic configuration of a sealed battery according to an embodiment of the present invention. It is a longitudinal cross-sectional view explaining the deformation | transformation state of the lead part of an electrical power collector. It is a cross-sectional view explaining the deformation | transformation state of the lead part of an electrical power collector. It is the schematic which shows an example of the usage condition of the battery which concerns on this invention. It is the schematic which shows an example of the usage condition of the battery which concerns on this invention. It is a cross-sectional view which shows the modification of the lead part of the electrical power collector which concerns on one Embodiment of this invention.

(Embodiment 1)
A battery 10 according to this embodiment shown in FIGS. 1 and 2 is, for example, a sealed battery that is a lithium ion battery, and includes an electrode bundle (element) 20 including a positive electrode plate 21 and a negative electrode plate 22, and a current collector 30. , 40 are accommodated in a battery case 50 as an exterior member together with a non-aqueous electrolyte (not shown). The upper part of the battery case 50 is sealed with a lid member 60. An insulating member 55 that covers the inner surface of the battery case 50 is provided in the battery case 50. Thereby, the battery case 50 is insulated from the electrode bundle 20 and the current collectors 30 and 40 accommodated therein.

  As will be described in detail later, one end side of the current collector 30 is connected to the positive electrode plate 21 of the electrode bundle 20, and the other end side of the current collector 30 is connected to the outside through a through hole 61 provided in the lid member 60. A protruding positive terminal member 70 is connected. One end of a current collector 40 is connected to the negative electrode plate 22. The other end side of the current collector 40 is connected to a negative electrode terminal member 80 that protrudes to the outside from a through hole 61 provided in the lid member 60.

  Insulating sheet members 90 are respectively disposed on the upper and lower surfaces of the lid member 60 so as to correspond to the openings of the through holes 61. The positive electrode terminal member 70 and the negative electrode terminal member 80 are insulated from the lid member 60 by the insulating sheet member 90.

  As shown in FIG. 3, in the electrode bundle 20, for example, a positive electrode plate 21 and a negative electrode plate 22 made of metal foil are offset stacked via a separator 23 to form a stacked body. Then, one end face of the wound body formed by winding the laminate in a cylindrical shape is a positive electrode surface 20a and the other end surface is a negative electrode surface 20b (see FIG. 1). The electrode bundle 20 according to the present embodiment is formed by winding a belt-like positive electrode plate 21 and a negative electrode plate 22 into a flat shape via a separator 23.

  Further, the strip-like positive electrode plate 21 is formed with an active material application part 25 to which an active material is applied, except for the non-application part 24 provided at one end in the width direction. Similarly, the negative electrode plate 22 is also provided with an active material application part 27 except for the non-application part 26. That is, the active material application part 25 is formed in the part which overlaps with the negative electrode plate 22 of the positive electrode plate 21, and the active material application part 27 is formed in the part which overlaps with the positive electrode plate 21 of the negative electrode plate 22.

  As shown in FIG. 4, a positive electrode binding portion 28 in which non-application portions 24 of a plurality of positive electrode plates 21 are bundled is formed on one end side of the electrode bundle 20 in the width direction (left and right direction in the drawing), that is, on the positive electrode surface 20 a side. Is formed. On the other end side in the width direction of the electrode bundle 20, that is, on the negative electrode surface 20 b side, a negative electrode binding portion 29 in which the non-application portions 26 of the plurality of negative electrode plates 22 are bundled is formed. The positive electrode binding portion 28 and the negative electrode binding portion 29 are bound by, for example, a substantially U-shaped binding member (not shown). The electrode bundle 20 according to the present embodiment is provided with two positive electrode binding portions 28 and two negative electrode binding portions 29. In addition, the number of the positive electrode binding parts 28 and the negative electrode binding parts 29 is not specifically limited, Each may be one and may be three or more.

  A current collector 30 is connected to each positive electrode binding portion 28 of the electrode bundle 20, and a current collector 40 side is connected to each negative electrode binding portion 29. The current collectors 30, 40 are plate-like terminal connection portions 31, 41 provided facing the lid member 60, and lead portions extending from the terminal connection portions 31, 41 facing the surface of the electrode bundle 20. 32, 42.

  The terminal connection portion 31 of the current collector 30 is connected to a positive electrode terminal member 70 that protrudes outside the lid member 60. The terminal connection portion 41 of the current collector 40 is connected to a negative electrode terminal member 80 that protrudes outside the lid member 60. Since the connection structure between the terminal connection portion 31 and the positive electrode terminal member 70 and the connection structure between the terminal connection portion 41 and the negative electrode terminal member 80 may be an existing structure, a detailed description of this point is omitted. To do.

  The lead portion 32 of the current collector 30 extends so as to face the surface of the electrode bundle 20, specifically, the surface of the positive electrode binding portion 28, and is connected to the outer surface of the positive electrode binding portion 28. . The lead portion 42 of the current collector 40 extends so as to face the surface of the negative electrode binding portion 29 and is connected to the outer surface of the negative electrode binding portion 29.

  In the present embodiment, the electrode bundle 20 includes two positive electrode binding portions 28 and two negative electrode binding portions 29. Therefore, the current collector 30 includes two lead portions 32 corresponding to the two positive electrode binding portions 28. Similarly, the current collector 40 includes two lead portions 42 corresponding to the two negative electrode binding portions 29. Specifically, the lead portion 32 of the current collector 30 is bifurcated from the terminal connection portion 31 with a predetermined width, and is extended to face the outer surface of each positive electrode binding portion 28. The lead portion 42 of the current collector 40 is bifurcated from the terminal connection portion 41 with a predetermined width, and is extended to face the outer surface of each negative electrode binding portion 29.

  Here, the base end portion side of the lead portion 32 of the current collector 30 is a flat portion 33 provided substantially parallel to the surface 20c of the electrode bundle 20 as shown in FIGS. In this embodiment, the flat surface portion 33 is connected to the positive electrode binding portion 28 by ultrasonic welding. Similarly, the base end side of the lead part 42 is also a flat part 43 provided substantially parallel to the surface 20c of the electrode bundle 20, and this flat part 43 is connected to the negative electrode binding part 29 by ultrasonic welding. ing. The method for joining the flat portion 33 and the positive electrode binding portion 28 and the method for joining the flat portion 43 and the negative electrode binding portion 29 are not limited to ultrasonic welding, and may be other methods.

  As shown in FIGS. 1, 2, and 4 (b), the tip side of each lead portion 32 of the current collector 30 is an inclined portion 34 that is inclined with respect to the surface 20 c of the electrode bundle 20. ing. That is, the inclined portion 34 is inclined at a predetermined angle with respect to the positive electrode surface 20 a of the electrode bundle 20. In other words, the lead portion 32 includes an inclined portion 34 that is disposed to be inclined with respect to the positive electrode surface 20a between the battery case 50 that is an exterior member and the positive electrode surface 20a. In the present embodiment, each lead portion 32 is provided such that an angle θ1 of the inclined portion 34 with respect to the surface 20c of the electrode bundle 20 is an acute angle. Similarly, the leading end side of each lead portion 42 of the current collector 40 is also an inclined portion 44 that is inclined with respect to the surface 20 c of the electrode bundle 20. That is, the inclined portion 44 is inclined at a predetermined angle with respect to the negative electrode surface 20 b of the electrode bundle 20. In other words, the lead portion 42 includes the inclined portion 44 that is disposed to be inclined with respect to the negative electrode surface 20b between the battery case 50 and the negative electrode surface 20b. In the present embodiment, each lead portion 42 is provided such that the angle θ2 of the inclined portion 44 with respect to the surface 20c of the electrode bundle 20 is an acute angle.

  Since the inclined portions 34 and 44 are provided on the lead portions 32 and 42 of the current collectors 30 and 40 as described above, when an impact (external force) is applied from the side of the battery case 50, internal short-circuiting occurs. Occurrence can be suppressed. For example, as shown in FIG. 5, when an external force is applied from the side of the battery case 50 and the lead part 32 is pressed toward the electrode bundle 20, the inclined part 34 of the lead part 32 rotates as shown in FIG. However, it moves (deforms) toward the electrode bundle 20 side. At this time, the plane portion 33 also rotates as the inclined portion 34 rotates. As a result, the lead portion 32 substantially comes into surface contact with the end surface of the electrode bundle 20 on the positive electrode surface 20a side. Thereby, the movement of the lead part 32 to the electrode bundle 20 side is restricted, and the entry of the lead part 32 into the electrode bundle 20 is suppressed. Further, the allowable deformation amount of the lead portion 32 until the short circuit can be increased. Therefore, occurrence of an internal short circuit in the battery 10 can be suppressed. Of course, the same effect can be obtained when the lead portion 42 of the current collector 40 is deformed.

  Further, when an external force is applied from the side of the battery case 50, the lead portions 32 and 42 are often deformed starting from the base end portions thereof, that is, the vicinity of the boundary with the terminal connection portions 31 and 41. For this reason, the deformation amount (movement amount) of the lead portions 32 and 42 toward the electrode bundle 20 tends to be the largest at the tip portions of the lead portions 32 and 42. That is, the tip portions of the lead portions 32 and 42 are most likely to enter the electrode bundle 20. In the present embodiment, inclined portions 34 and 44 are provided at the tip portions of the lead portions 32 and 42. Accordingly, it is possible to more reliably suppress the lead portions 32 and 42 from entering the electrode bundle 20.

  In the present embodiment, in consideration of workability when connecting the lead portions 32 and 42 and the positive and negative electrode binding portions 28 and 29 by ultrasonic welding or the like, the lead portions 32 and 42 are provided with flat portions 33 and 43. However, as long as the lead parts 32 and 42 and the positive and negative electrode binding parts 28 and 29 can be connected well, the entire lead parts 32 and 42 may be inclined parts 34 and 44. Thereby, the approach of the lead portions 32 and 42 into the electrode bundle 20 can be more reliably suppressed.

  In addition, since the lead portions 32 and 42 are provided with the inclined portions 34 and 44, particularly the entire lead portions 32 and 42 are the inclined portions 34 and 44, the space required for the lead portions 32 and 42 is conventionally increased. It can be made smaller. Accordingly, the ratio of the electrode bundle 20 to the battery case 50 increases. Therefore, the battery capacity per unit volume can be improved.

  By the way, as shown in FIG. 7A, for example, the battery 10 which is a square sealed battery is collectively stored in a small case 110 in a plurality of pieces (for example, about 5 to 8 pieces). Is done. Further, a plurality of small cases 110 are housed side by side in a large case (casing) 120 that includes a battery tray 121 and a battery cover 122 and has a larger volume than the small case 110, thereby forming a battery pack 130. That is, in the battery pack 130, the battery 10 is stored in a double case structure of the small case 110 and the large case 120. And as shown in FIG.7 (b), this battery pack 130 is mounted in vehicles 200, such as an electric vehicle. Therefore, if the battery 10 is square, the dead space can be minimized and the space efficiency can be improved.

  The arrangement of the battery pack 130 is not particularly limited. The battery pack 130 is attached under the floor in the vicinity of the center of the vehicle 200 in consideration of, for example, lowering the center of gravity of the vehicle 200 and improving the motion performance of the vehicle 200, and securing a vehicle interior space (FIG. 7B). reference). Alternatively, the battery pack 130 may be attached to the trunk room at the rear of the vehicle 200 in consideration of lowering the overall vehicle height of the vehicle 200, convenience in the passenger compartment of the vehicle 200, and the like.

  Furthermore, the direction of the battery 10 with respect to the vehicle 200 is not particularly limited. For example, the battery 10 may be provided such that the longitudinal direction thereof coincides with the front-rear direction of the vehicle 200, or may be provided such that the longitudinal direction thereof coincides with the vertical direction of the vehicle 200. Good. In any case, it is preferable to efficiently arrange the dead space so as to reduce the dead space in consideration of various conditions such as securing the cabin space of the vehicle 200 and lowering the center of gravity of the vehicle 200.

  When the arrangement of the battery 10 is appropriately determined in consideration of various conditions as described above, the current collectors 30 and 40 may be arranged outward with respect to the center of the vehicle 200. That is, as shown in FIG. 8A, the batteries 10 may be arranged so that the positive electrode surface 20a and the negative electrode surface 20b side of the electrode bundle 20 face the front and rear direction of the vehicle, or FIG. ), The battery 10 may be arranged so that the positive electrode surface 20a and the negative electrode surface 20b of the electrode bundle 20 face the outside in the left-right direction of the vehicle. If the battery 10 is arranged in such a direction, for example, when the vehicle 200 collides and an external force is applied to the battery 10, a short circuit due to deformation of the lead portions 32 and 42 is likely to occur. However, according to the configuration of the present invention, it is possible to effectively suppress a short circuit due to the deformation of the lead portions 32 and 42 regardless of the orientation of the battery 10 with respect to the vehicle 200.

  In the present embodiment, the lead portions 32 and 42 are provided so that the inclined angle of the inclined portions 34 and 44 with respect to the surface 20c of the electrode bundle 20 is an acute angle. It is not limited to this. For example, the lead portions 32 and 42 may have substantially the same inclination of the inclined portions 34 and 44 with respect to the positive electrode surface 20a or the negative electrode surface 20b. That is, in the above-described embodiment, each of the lead portions 32 and 42 is provided with two inclined portions 34 and 44 in the shape of a letter C. For example, as shown in FIGS. 9A and 9B, The inclined portions 34 and 44 may be provided so as to be substantially parallel. Thus, when the lead portions 32 and 42 and the positive electrode binding portion 28 or the negative electrode binding portion 29 are joined by welding or the like, the same direction is applied to the joint portions of the both. Since it can be accessed from, the workability is improved.

  Furthermore, each lead part 32 and 42 may be provided so that the inclination angle with respect to the surface 20c of the electrode bundle 20 of each inclination part 34 and 44 may become an obtuse angle, for example, as shown in FIG.9 (c). . Of course, even with such a configuration, the lead portions 32 and 42 can be prevented from entering the electrode bundle 20.

  As mentioned above, although one Embodiment of this invention was described, of course, this invention is not limited to the above-mentioned embodiment.

DESCRIPTION OF SYMBOLS 10 Battery 20 Electrode bundle 21 Positive electrode plate 22 Negative electrode plate 23 Separator 24, 26 Non-application part 25, 27 Active material application part 28 Positive electrode binding part 29 Negative electrode binding part 30, 40 Current collector 31, 41 Terminal connection part 32, 42 Lead Part 33, 43 Plane part 34, 44 Inclined part 50 Battery case 60 Lid member 61 Through hole 70 Positive electrode terminal member 80 Negative electrode terminal member 90 Insulating sheet member 110 Small case 120 Large case 130 Battery pack 200 Vehicle

Claims (2)

An electrode in which a positive electrode plate and a negative electrode plate are offset laminated via a separator to form a laminated body, and one end face of a wound body formed by winding the laminated body is a positive electrode surface and the other end face is a negative electrode surface A bunch,
A plurality of lead portions arranged corresponding to each of the positive electrode surface and the negative electrode surface of the electrode bundle and connected to the positive electrode surface; and a plurality of lead portions connected to the negative electrode surface;
A rectangular exterior member that accommodates the electrode bundle and the lead portion;
Have
The lead portion is between the exterior member and the positive electrode surface or the negative electrode surface.
An inclined portion arranged to be inclined with respect to the positive electrode surface or the negative electrode surface;
A plane portion arranged in parallel to the positive electrode surface or the negative electrode surface,
The plurality of lead portions connected to the positive electrode surface have the same inclination direction between the inclined portions and substantially the same inclination with respect to the positive electrode surface,
The plurality of lead portions connected to the negative electrode surface have the same inclination direction of the inclined portions and substantially the same inclination with respect to the negative electrode surface. The battery according to claim 1 .
The battery is characterized in that the entire portion of the lead portion overlapping the positive electrode surface or the negative electrode surface is the inclined portion.

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