Cutting device of electrode body

Abstract

To provide a cutting device of an electrode body which stably cuts off from each other a substance part and a lamination part of the electrode body to improve battery quality.SOLUTION: A cutting device 100 of an electrode body 1 comprises: a plurality of split tip-retainers 30 (31, 32); a plurality of split upper-blades 10 (11, 12A, 12B, 13A, 13B); a lower blade 20 not split; tip retainer adjustment means 50 which adjusts holding force of each of the tip retainers 30 (31, 32) for each of split portions of the tip retainers 30; and upper blade adjustment means 40 which adjusts height of each of the upper blades 10 (11, 12A, 12B, 13A, 13B) for each of split portions of the upper blades 10.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cutting device for an electrode body.

Background Art

[0002] In an electrode body constituting a battery, after a negative electrode, a separator, and a positive electrode are sequentially coated on a substrate portion made of a metal foil to form a laminated portion, coating defects and lamination misalignments that occur at the end of the electrode body and do not function as a battery are removed to maximize battery performance.

[0003] The cutting device for an electrode body described in Patent Document 1 holds the electrode body placed on the lower blade with a pre-pressing portion, and cuts the electrode body by lowering the upper blade around the lower blade.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the cutting device for an electrode body described in Patent Document 1, the pressing force of the pre-pressing portion and the clearance between the upper blade and the lower blade with respect to the substrate portion and the laminated portion of the electrode body are made uniform, and they cannot cope with the thickness difference between the substrate portion and the laminated portion.

[0006] For this reason, the processing applied by the upper blade and the lower blade to the substrate portion and the laminated portion becomes unstable, and it is difficult to satisfy battery quality (no sag (interlayer contact), no burrs or curl, dimensional accuracy).

[0007] An object of the present invention is to stably cut the substrate portion and the laminated portion of the electrode body and improve battery quality.

Means for Solving the Problems

[0008] The invention according to claim 1 is a cutting device for an electrode body, which comprises a plurality of divided front pressing parts, a plurality of divided upper blades, an undivided lower blade, a front pressing adjustment means for adjusting the pressing force of each front pressing part for each divided part of the front pressing part, and an upper blade adjustment means for adjusting the height of each upper blade for each divided part of the upper blade.

Effects of the Invention

[0009] (a) By adjusting the pressing force of each front pressing part for each divided part of the front pressing part by the front pressing adjustment means, the pressing force of each front pressing part applied to each of the substrate part and the laminated part having different thicknesses in the electrode body can be adjusted. Therefore, the vicinity of each cutting position of the substrate part and the laminated part of the electrode body can be reliably constrained on the upper surface of the lower blade at the stage immediately before the start of their cutting. Thereby, the movement during the cutting of each of the substrate part and the laminated part can be suppressed, and the substrate part and the laminated part can be stably cut by the upper blade and the lower blade, and the dimensional quality can be improved.

[0010] (b) By using a plurality of divided upper blades and an undivided lower blade, the clearance formed by the upper blade corresponding to each of the substrate part and the laminated part with respect to the lower blade can be adjusted for each of the substrate part and the laminated part having different thicknesses in the electrode body. Thereby, the clearance for the thin part (substrate part) is set small, and the clearance for the thick part (laminated part) is set large, so that the substrate part and the laminated part can be stably cut by the upper blade and the lower blade, and the battery quality can be improved.

[0011] (c) By the upper blade adjustment means, the height of each upper blade can be adjusted for each divided part of the upper blade, and a time difference can be provided in the cutting timing of each upper blade with respect to each of the substrate part and the laminated part having different thicknesses in the electrode body. Thereby, the processing resistance received by each upper blade from the electrode body is dispersed over time, and the electrode body can be processed with a low thrust force.

[0012] (d) According to the above (a) to (c), when cutting the substrate part and the laminated part of the electrode body in one stroke, these substrate part and laminated part can be stably cut with low thrust, and the battery quality (no sag (interlayer contact), no burrs or chips, dimensional accuracy) can be improved.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] FIG. 1 shows a cutting device 100 according to an embodiment of the present invention, which has a punch holder 101 and a die holder 102 that face each other vertically. The punch holder 101 is guided by a guide post 103 and moves up and down with respect to the die holder 102 by obtaining a driving force such as hydraulic pressure or electric power.

[0015] The cutting device 100 cuts the electrode body 1 constituting the battery, and has a plurality of divided upper blades 10 supported on the lower surface of the punch holder 101, an undivided lower blade 20 supported on the upper surface of the die holder 102, and a plurality of divided front pressing parts 30 provided on the lower surface of the punch holder 101. In this embodiment, the front pressing part 30 enables the electrode body 1 held on the lower blade 20 to be cut by the upper blade 10.

[0016] The electrode body 1 is configured to have a substrate portion 2 and a stacked portion 3 as shown in FIG. 2, for example. The substrate portion 2 is formed from a metal foil such as aluminum, and the stacked portion 3 is formed by sequentially coating and stacking a powdery negative electrode 3A, a powdery separator 3B, and a powdery positive electrode 3C on the upper and lower surfaces of a part of the substrate portion 2.

[0017] As shown in FIG. 2, the electrode body 1 has a rectangular shape in plan view (FIG. 2(A)), the substrate portion 2 and the stacked portion 3 have substantially the same width in the direction along the short side, the substrate portion 2 extends from one end side to the other end side along the long side, and the stacked portion 3 is formed in the range from the middle portion to the other end side along the long side. The substrate portion 2 has a film thickness ta of, for example, 10 μm, and the stacked portion 3 has a film thickness tb of, for example, 150 μm.

[0018] In order to remove coating defects and stacking misalignment of the stacked portion 3 (negative electrode 3A, separator 3B, positive electrode 3C) stacked on the substrate portion 2 and maximize battery performance, the outer edge portion of the electrode body 1 is cut by a cutting device 100.

[0019] As shown in FIGS. 1, 3, and 4, the cutting device 100 divides the upper blade 10 into an upper blade 11 that cuts the side of the stacked portion 3 of one of the short sides of the electrode body 1, upper blades 12A and 12B that cut the substrate portion 2 and the stacked portion 3, respectively, on one of the long sides of the electrode body 1, and upper blades 13A and 13B that cut the substrate portion 2 and the stacked portion 3, respectively, on the other long side of the electrode body 1.

[0020] At this time, the cutting device 100 has upper blade adjusting means 40 (not shown) for adjusting the height of each of the upper blades 11, 12A, 12B, 13A, and 13B for each of the above-described dividing portions of the upper blade 10.

[0021] That is, the cutting device 100 changes the protruding height of the upper blade 10 with respect to the lower blade 20 for each side of the electrode body 1. As shown in FIG. 1, the protruding height of the upper blade 11 is increased, the protruding heights of the upper blades 12A and 12B are set to an intermediate value, and the protruding heights of the upper blades 13A and 13B are decreased. As a result, in a single downward movement of the punch holder 101, the cutting device 100 first cuts the laminated portion 3 of one of the short sides of the electrode body 1 with the upper blade 11, and then cuts the substrate portion 2 and the laminated portion 3 on one long side of the electrode body 1 with the upper blades 12A and 12B. Thereafter, the substrate portion 2 and the laminated portion 3 on the other long side of the electrode body 1 are cut with the upper blades 13A and 13B. As a result, each side of the electrode body 1 can be cut in the order of i, ii, and iii shown in FIG. 2(A).

[0022] The cutting device 100 has a plurality of divided upper blades 10 (upper blade 11, upper blades 12A and 12B, upper blades 13A and 13B) and an undivided lower blade 20, so that the clearance formed by each of the upper blades 11, 12A, 12B, 13A, and 13B with respect to the lower blade can be adjusted to an appropriate value according to the thickness of the object to be cut. For example, as shown in FIG. 4, the clearance C1 of the upper blades 12A and 13A for cutting the substrate portion 2 with a small thickness with respect to the lower blade 20 is small, and the clearance C2 of the upper blades 12B and 13B for cutting the laminated portion 3 with a large thickness with respect to the lower blade 20 is set large (C1 < C2).

[0023] The cutting device 100 divides the pre-pressing portion 30 into a pre-pressing portion 31 that holds the substrate portion 2 of the electrode body 1 on the lower blade 20 and a pre-pressing portion 32 that holds the laminated portion 3 of the electrode body 1 on the lower blade 20.

[0024] At this time, the cutting device 100 has a pre-pressing adjustment means 50 that adjusts so that the pressing forces F1 and F2 (FIG. 3) applied by the respective pre-pressing portions 31 and 32 to the corresponding substrate portion 2 and laminated portion 3 can be made independent of each other for each of the above-described divided portions of the pre-pressing portion 30.

[0025] The cutting device 100 cuts the electrode body 1 in a single cutting stroke according to the following (1) to (3) (FIG. 5).

[0026] (1) Place the electrode body 1 on top of the lower blade 20 (Fig. 5(A)). Then, lower the punch holder 101 from its original position and perform the following cutting operation.

[0027] (2) Hold the substrate portion 2 and the stacked portion 3 of the electrode body 1 against the lower blade 20 by the respective pressing portions 31 and 32 of the pre-pressing portion 30 (Fig. 5(B)).

[0028] As shown in Fig. 3, the pre-pressing portion 30 holds the substrate portion 2 by the pressing force F1 of the pressing portion 31 and holds the stacked portion 3 by the pressing force F2 of the pressing portion 32.

[0029] (3) Cut the substrate portion 2 and the stacked portion 3 of the electrode body 1 corresponding to them in the order of i, ii, iii (Fig. 2(A)) by the respective upper blades 11, 12A, 12B, 13A, and 13B of the upper blade 10 (Fig. 5(C)). In Fig. 5(C), k indicates the cutting chips.

[0030] Therefore, according to the present embodiment, the following effects can be obtained. (a) By adjusting the pressing forces of the respective pressing portions 31 and 32 for each divided portion of the pre-pressing portion 30 (31, 32) by the pre-pressing adjustment means 50, the pressing forces of the respective pressing portions 31 and 32 applied to the substrate portion 2 and the stacked portion 3 having different thicknesses in the electrode body 1 can be adjusted. Therefore, the portions near the cutting positions of the substrate portion 2 and the stacked portion 3 of the electrode body 1 can be reliably restrained on top of the lower blade 20 at the stage immediately before the start of their cutting. Thereby, the movement during the cutting of the substrate portion 2 and the stacked portion 3 can be suppressed, and the substrate portion 2 and the stacked portion 3 can be stably cut by the upper blade 10 and the lower blade 20, and the dimensional quality can be improved.

[0031] (b) By using a plurality of divided upper blades 10 (11, 12A, 12B, 13A, 13B) and an undivided lower blade 20, for each of the substrate portion 2 and the laminated portion 3 having different thicknesses in the electrode body 1, the clearance formed by the corresponding upper blade 10 with respect to the lower blade 20 for each of the substrate portion 2 and the laminated portion 3 can be adjusted. Thereby, the clearance with respect to the thin portion (substrate portion 2) is made small, and the clearance with respect to the thick portion (laminated portion 3) is set large, so that the substrate portion 2 and the laminated portion 3 can be stably cut by the upper blade 10 and the lower blade 20, and the battery quality can be improved.

[0032] (c) By the upper blade adjusting means, the height of each upper blade 10 (11, 12A, 12B, 13A, 13B) can be adjusted for each divided portion of the upper blade 10, and a time difference can be provided in the cutting timing of each upper blade 10 (11, 12A, 12B, 13A, 13B) with respect to each of the substrate portion 2 and the laminated portion 3 having different thicknesses in the electrode body 1. Thereby, the processing resistance received by each upper blade 10 (11, 12A, 12B, 13A, 13B) from the electrode body 1 is dispersed over time, and the electrode body 1 can be processed with low thrust.

[0033] (d) By the above (a) to (c), when cutting the substrate portion 2 and the laminated portion 3 of the electrode body 1 in one stroke, the substrate portion 2 and the laminated portion 3 can be stably cut with low thrust, and the battery quality (no sag (interlayer contact), no burrs or chips, dimensional accuracy) can be improved.

[0034] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention.

Industrial Applicability

[0035] According to the present invention, the substrate portion and the laminated portion of the electrode body can be stably cut, and the battery quality can be improved.

Explanation of Reference Numerals

[0036] 1 Electrode body 10 (11, 12A, 12B, 13A, 13B) Upper blade 20 Lower blade 30 (31, 32) Front pressing part 40 Upper blade adjusting means 50 Front pressing adjusting means 100 Cutting device

Claims

【Claim 1】 In an electrode body cutting device, a plurality of divided front pressing parts, a plurality of divided upper blades, an undivided lower blade, a front pressing adjustment means for adjusting the pressing force of each front pressing part for each divided part of the front pressing part, and an upper blade adjustment means for adjusting the height of each upper blade for each divided part of the upper blade, characterized by an electrode body cutting device.

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