Tensile test method for terminals in stacked battery

Abstract

To provide a method that facilitates tensile testing to check terminal bonding in the manufacture of stacked batteries.SOLUTION: A tensile test method for a terminal in a stacked battery having a terminal 20 joined to an electrode foil 14 includes the steps of attaching a protrusion 32 provided on a tensile jig 30 to a hole provided in the terminal, and conducting a tensile test using the tensile jig.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present application relates to a method for tensile testing terminals provided in a stacked battery. [Background technology]

[0002] Patent Document 1 discloses that a voltage detection tab is joined to a power generating element (electrode foil) so that the voltage can be detected for each battery unit. Patent Document 2 discloses that in a bipolar battery, the electrode tabs have hole-shaped portions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-235428 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-128038 Summary of the Invention [Problem to be solved by the invention]

[0004] When conducting a tensile test to check the connection of a voltage detection tab (terminal) joined to a power generating element, there is a possibility that the voltage detection tab and the chuck used in the tensile test may slip, making it impossible to perform the test properly. In Patent Document 2, a hole-shaped portion is provided, but the hole-shaped portion is provided in the adhesive region with the exterior material and cannot be used during the tensile test.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a method for easily performing a tensile test to check the bonding of terminals in the manufacture of a stacked battery. [Means for solving the problem]

[0006] The present application discloses a method for tensile testing a terminal in a stacked battery having a terminal joined to an electrode foil, the method comprising the steps of attaching a protrusion provided on a tensile jig to a hole provided in the terminal, and performing a tensile test using the tensile jig. [Effects of the Invention]

[0007] According to the terminal tensile test method disclosed herein, the tensile jig is fixed to the terminal by attaching a protrusion provided on the tensile jig to the hole portion of the terminal, allowing the tensile test to be performed without slippage. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a stacked battery 10, focusing on the portion where the terminals 20 are exposed. [Figure 2] FIG. 2 is a perspective view of one terminal 20 and the terminal 20 bonded to an electrode foil. [Figure 3] FIG. 3 is a perspective view showing a terminal 20 according to a modified example taken from the same perspective as FIG. [Figure 4] FIG. 4 is a perspective view showing a state in which a tension jig 30 is placed on the terminal 20. As shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1. Stacked battery First, we will explain the stacked battery 10 equipped with terminals 20 that are the subject of the tensile test. The stacked battery 10 is a battery formed by stacking multiple flat-plate-shaped unit cells. Therefore, the stacked battery 10 is thicker than the unit cells and has a flat plate shape, front and back surfaces, and a side surface 11 that forms the outer peripheral end surface. Figure 1 shows a portion of the side surface 11 equipped with terminals 20. Figure 1 also shows the axial directions of an xyz Cartesian coordinate system. The x direction is the direction in which the edges of the front and back surfaces of stacked battery 10 extend at the side surface 11 of interest in Figure 1, the y direction is the direction in which the multiple cells are stacked, and the z direction is the direction perpendicular to the x and y directions.

[0010] 1.1. Cells and batteries The configuration of the unit cell is not particularly limited and may be as known. That is, the unit cell has a laminated structure in which a positive electrode layer, an electrode foil 14 (see FIG. 2), and a negative electrode layer are laminated. In the case of a bipolar electrode, a positive electrode layer is disposed on one side of one electrode foil, and a negative electrode layer is disposed on the other side.

[0011] A plurality of such cells are stacked with separators sandwiched between adjacent cells to form a stacked battery 10. A sealing material 16 (see FIG. 2) is disposed at the outer peripheral edge between adjacent cells in the stacking direction, sealing the inside of the stacked battery 10 from the outside.

[0012] 1.2.Terminals 1, in this embodiment, terminal 20 is a terminal to which a voltage meter is connected in order to obtain the voltage value of each cell, and is provided for each cell, with one end, or the base side, being disposed inside the cell and electrically connected to the electrode foil 14 of the cell, and the other end, or the tip side, protruding outward in the z direction.

[0013] 2 shows a perspective view of one terminal 20, and also shows a schematic diagram of the terminal 20 being joined to the electrode foil 14. The hatched portion in FIG. As can be seen from FIG. 2, the terminal 20 has a connection portion 21 and an extension portion 22. The connection part 21 is a plate-like member having its front and back surfaces in the xz plane, and is disposed inside the cell to be connected to the electrode foil 14 of the cell. Here, the connection part 21 is provided with a hole 21a that penetrates in the thickness direction (y direction). The extension portion 22 has one end located in the connection portion 21 and the other end extending in the z direction, and is a long, narrow strip-like member with its front and back surfaces on the x-z plane and extending significantly in the z direction. As can be seen in Figure 2, the extension portion 22 allows the terminal 20 to protrude outward from the side surface 11. This extension portion 22 protrudes from the side surface 11 of the stacked battery 10 (see Figure 1).

[0014] 2, such terminal 20 is bonded to the surface of electrode foil 14 exposed at cutout 16a provided in sealing material 16. At this time, one surface of connection portion 21 is overlapped and bonded to the surface of electrode foil 14, but hole portion 21a is positioned so as not to overlap electrode foil 14.

[0015] Fig. 3 shows a modified terminal 20. Fig. 3 is a view from the same perspective as Fig. 2. In this modified example, the tip of extension portion 22 (the side opposite to connection portion 21) is thickened in the y direction, and a hole 21a is provided at this tip, penetrating in the x direction. Even with this type of terminal 20, the tensile test described below can be performed.

[0016] 2. Tensile jig 4 shows a state in which a tension jig 30, which is a jig for tension testing, is placed on the terminal 20 in FIG. The specific shape of the main body 31 is not particularly limited, but in this embodiment it is a block-shaped member in the shape of a rectangular parallelepiped. The protrusion 32 is a protruding member that protrudes from the surface of the main body 31, and the shape of the protrusion 32 is configured so that it can be inserted into the hole of the hole 21a of the terminal 20. In this embodiment, the tip of the protrusion 32 is shaped to be tapered so that it can be easily inserted into the hole of the hole 21a.

[0017] 3. Terminal tension test method and effects The tensile test of the terminal is carried out, for example, as follows. First, as shown in FIG. 4, the protrusion 32 of the tension jig 30 is inserted into the hole of the hole 21a of the terminal 20, and the tension jig 30 is attached to the hole 21a of the terminal 20. Next, from this state, as shown by arrow P in FIG. 4, terminal 20 is pulled with a predetermined load in the direction in which terminal 20 extends (z direction in FIG. 4).

[0018] This makes it possible to determine whether terminal 20 is properly joined to electrode foil 14. If the joining is not proper, terminal 20 will come off electrode foil 14 with an unintended low tensile force. According to the tensile test method of the present disclosure, terminal 20 and tensile jig 30 are engaged with hole 21a and protrusion 32, so that a proper tensile test can be performed without slippage or the like occurring when pulled. Because terminal 20 is very thin and located in the very narrow area of ​​notch 16a of sealing material 16, problems were likely to occur during the series of tests that required properly grasping, holding, and pulling the terminal during the tensile test. In contrast, according to the present disclosure, terminal 20 can be reliably pulled by tensile jig 30 without slipping. [Explanation of symbols]

[0019] 10... stacked battery, 11... side surface, 20... terminal, 21... connection portion, 21a... hole portion, 22... extension portion, 30... tension jig, 31... main body, 32... protrusion portion

Claims

[Claim 1] A method for tensile testing a terminal in a laminated battery having a terminal joined to an electrode foil, comprising: a step of attaching a protrusion provided on a tension jig to a hole provided in the terminal; and performing a tensile test using the tensile jig. Tensile test method for terminals.

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