WO2018012789A1 - Secondary battery - Google Patents

Abstract

The present invention provides a secondary battery comprising a pole plate which is coated on one or both surfaces with an electrode active material, and comprises a first side, and a second side opposite to the first side, a third side perpendicular to the first side and the second side, and a fourth side opposite to the third side. As an example, disclosed is a secondary battery which comprises one or more connection parts formed in a connecting portion of the first side and the third side or the fourth side, or a connecting portion of the second side and the third side or the fourth side, wherein the connection part comprises two or more inclination parts, which extend from the first side to the third side or the fourth side, or extend from the second side to the third side or the fourth side, but are embedded into the internal direction of the pole plate, and form an obtuse angle with respect to the third side or the fourth side.

Description

Secondary battery

The present invention relates to a secondary battery.

In general, a secondary battery is a battery that can be charged and discharged unlike a primary battery that cannot be charged. In the case of a low-capacity battery in which one battery cell is packed in a pack form, a secondary battery is used in portable electronic devices such as a mobile phone and a camcorder. Large capacity batteries with dozens of cells connected are used as motor power sources for electric bicycles, electric scooters, hybrid cars, and electric cars.

Secondary batteries are manufactured in various shapes, and typical shapes include square, cylindrical, and pouch types. The secondary battery is configured by accommodating an electrode assembly and an electrolyte in a case, and installing a cap plate on the case. In addition, the electrode assembly is connected to the electrode tab, the terminal of the positive electrode, etc., which is exposed or protruded to the outside through the cap plate.

The electrode assembly of the secondary battery is formed with a separator interposed between the positive electrode plate, the negative electrode plate, and the positive electrode plate and the negative electrode plate. The electrode assembly may be formed by winding a laminate of a positive electrode plate, a negative electrode plate, and a separator, or may be formed by stacking a plurality of positive electrode plates, a negative electrode plate, and a separator. In the method of forming an electrode assembly by stacking a plurality of electrode plates, the positive electrode plate and the negative electrode plate are alternately stacked at the boundary of the separator.

In order to produce an electrode plate to be laminated, the electrode sheet should be separated by cutting an electrode sheet, and the electrode plate is often separated by a punching method while transferring the electrode sheet along a transfer line.

The present invention provides a secondary battery including an electrode sheet having a cut portion in the upper and lower parts, and a pole plate manufactured by cutting the electrode sheet to manufacture a plurality of electrode plates.

In the secondary battery according to the present invention, an electrode active material is coated on one or both surfaces thereof, and includes a first side and a second side facing the first side, a third side perpendicular to the first side and the second side, and the second side. A pole plate having a fourth side facing the three sides, the connecting portion of the first side and the third side or the fourth side, or a connecting portion of the second side and the third side or the fourth side; One or more connecting portions formed in the connecting portion, wherein the connecting portion starts from the first side and continues to the third or fourth side, or starts from the second side and continues to the third or fourth side. It is formed to be recessed in the inner direction of the pole plate, and includes two or more inclined portions forming an obtuse angle with respect to the third side or the fourth side.

Wherein the inclined portion may include a first inclined portion extending from an at least one of the first side and the second side to be inclined in an inward direction of the electrode plate; And a second inclined portion starting from the end of the first inclined portion and extending in an inward direction of the electrode plate to be inclined.

The first angle formed by the first inclined portion based on the third side or the fourth side may be greater than the second angle formed by the second inclined portion.

The inclined portion may further include: a first inclined portion formed to be inclined to extend inwardly of the electrode plate starting from at least one of the first side and the second side; And a second inclined portion extending from the end of the first inclined portion to be inclined in the inward direction of the pole plate, the acute angle being formed based on the third side or the fourth side, and the end of the second inclined portion. It may further include a third inclined portion extending in an outward direction of the electrode plate to be inclined.

In addition, an angle formed by the third inclined portion based on the third side or the fourth side may be 45 ° or more.

In addition, the connecting portion includes a first connecting portion formed on the first side and a second connecting portion formed on the second side, and the second side of the electrode plate is parallel to the first side and the parallel portion; It may include a curved portion extending from the end of the parallel portion in the inward direction of the pole plate, the inclined portion of the second connecting portion formed on the second side may be formed extending from the end of the curved portion in the inward direction of the pole plate In addition, the inclined portion of the second connecting portion formed on the second side of the pole plate may include an inclined portion formed inclined to extend in the inward direction of the pole plate starting from the second side.

In addition, the inclined portion of the first connecting portion formed on the first side of the pole plate, the first inclined portion formed inclined to extend in the inward direction of the pole plate starting from the first side; And a second inclined portion extending from the end of the first inclined portion to be inclined in the inward direction of the pole plate, the acute angle being formed based on the third side or the fourth side, and the end of the second inclined portion. It may further include a third inclined portion extending in an outward direction of the electrode plate to be inclined.

In addition, the inclined portion may further include at least one inclined portion to form a reservation based on the third side or the fourth side.

The inclined portion may further include: a first inclined portion formed to be inclined to extend inwardly of the electrode plate starting from at least one of the first side and the second side; A second inclined portion starting at the end of the first inclined portion and extending in an inward direction of the electrode plate to be inclined; And a third inclined portion starting from at least one of the first side and the second side and extending in an inward direction of the electrode plate to be inclined in a direction facing the first inclined portion and the second inclined portion.

Electrode sheet of the present invention is provided with a cutting portion in the upper and lower, so that the oblique angled connection portion is formed on the pole plate produced by cutting the electrode sheet, it is possible to reduce the precision required for the installation, passing through the roller for laminating after the pole plate is laminated At the time, the impact transmitted from the roller is reduced to prevent the active material coated on the upper part of the plate from falling off.

1 is a plan view of an electrode sheet according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A of FIG. 1.

3 is a plan view of an electrode plate formed by cutting an electrode sheet according to an exemplary embodiment of the present invention.

4 is an enlarged view of a portion B of FIG. 3.

5 is an enlarged view of a portion B ′ of FIG. 3.

Figure 6 shows that the active material is coated on the electrode plate according to an embodiment of the present invention is introduced between the rollers.

7 illustrates that the active material is coated on the electrode plate according to an embodiment of the present invention and passed through a roller.

8 is a plan view of an electrode sheet according to another embodiment of the present invention.

9 is an enlarged view of a portion C of FIG. 8.

10 is a plan view of an electrode plate formed by cutting an electrode sheet according to another exemplary embodiment of the present invention.

FIG. 11 is an enlarged view of portion D of FIG. 10.

FIG. 12 is an enlarged view of a portion D ′ of FIG. 10.

13 is a plan view of an electrode sheet according to another embodiment of the present invention.

FIG. 14 is an enlarged view of portion E of FIG. 13.

FIG. 15 is an enlarged view of a portion F of FIG. 13.

16 is a plan view of an electrode plate formed by cutting an electrode sheet according to still another exemplary embodiment of the present invention.

FIG. 17 is an enlarged view of a portion G of FIG. 16.

FIG. 18 is an enlarged view of a portion G ′ of FIG. 16.

19 is an enlarged view of a portion H of FIG. 16.

20 is an enlarged view of a portion 'H' of FIG. 16.

21 is a plan view of an electrode sheet according to another embodiment of the present invention.

FIG. 22 is an enlarged view of a portion G of FIG. 21.

23 is a plan view of an electrode plate formed by cutting an electrode sheet according to still another exemplary embodiment of the present invention.

24 is an enlarged view of a portion H of FIG. 23.

FIG. 25 is an enlarged view of a portion 'H' of FIG. 23.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, and the following examples can be modified in various other forms, and the scope of the present invention is It is not limited to an Example. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art.

In addition, in the following drawings, the thickness or size of each layer is exaggerated for convenience and clarity of description, the same reference numerals in the drawings refer to the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items. In addition, the term "connected" in this specification means not only the case where the A member and the B member are directly connected, but also the case where the A member and the B member are indirectly connected by interposing the C member between the A member and the B member. do.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. Also, as used herein, "comprise, include" and / or "comprising, including" means that the features, numbers, steps, actions, members, elements, and / or groups thereof mentioned. It is intended to specify the existence and not to exclude the presence or addition of one or more other shapes, numbers, operations, members, elements and / or groups.

Although the terms first, second, etc. are used herein to describe various members, parts, regions, layers, and / or parts, these members, parts, regions, layers, and / or parts are defined by these terms. It is obvious that not. These terms are only used to distinguish one member, part, region, layer or portion from another region, layer or portion. Accordingly, the first member, part, region, layer or portion, which will be described below, may refer to the second member, component, region, layer or portion without departing from the teachings of the present invention.

Terms relating to spaces such as "beneath", "below", "lower", "above", and "upper" are associated with one element or feature shown in the figures. It can be used for easy understanding of other elements or features. Terms related to this space are for easy understanding of the present invention according to various process conditions or use conditions of the present invention, and are not intended to limit the present invention. For example, if an element or feature in the figures is inverted, the element or feature described as "bottom" or "bottom" will be "top" or "top". Thus, "below" is a concept encompassing "top" or "bottom".

1 is a plan view of an electrode sheet according to an embodiment of the present invention. FIG. 2 is an enlarged view of a portion A of FIG. 1. 3 is a plan view of an electrode plate formed by cutting an electrode sheet according to an exemplary embodiment of the present invention. 4 is an enlarged view of a portion B of FIG. 3. 5 is an enlarged view of a portion B ′ of FIG. 3.

Referring to FIG. 1, an electrode sheet 100 according to an exemplary embodiment of the present invention may include a pole plate 110, an electrode tab 120, and a cutting unit 130.

The pole plate 110 may be cut and separated from the cut portion 130, and the cut and separated pole plate 110 may be a positive electrode plate or a negative electrode plate. In the positive electrode plate and the negative electrode plate, separators are stacked therebetween to form an electrode assembly. That is, the separator is stacked on the positive electrode plate, the negative electrode plate is laminated on the separator, the positive electrode plate is laminated again on the separator upper surface on the negative electrode plate, and the separator and the negative electrode plate are sequentially stacked again to form an electrode assembly.

On one side or both sides of the electrode plate 110, a coating portion coated with an active material is formed, and an upper portion of the electrode plate 110 is formed with an uncoated portion having no active material coated thereon. The uncoated portion becomes a passage for current flow between the electrode of the secondary battery and the outside.

When the electrode plate 110 is a positive electrode plate, the material of the electrode sheet 100 may be a metal material such as aluminum, and an active material based on lithium-based oxide may be applied. When the electrode plate 110 is a negative electrode plate, the electrode sheet 100 may be made of metal such as copper, and an active material including a carbon material as a main component may be coated.

The separator prevents a short between the positive electrode plate and the negative electrode plate, and serves to enable movement of ions. The separator may be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene.

The electrode tab 120 may extend upward from the upper end of the electrode sheet 100 at regular intervals to form a bar. The electrode tab 120 of the positive electrode plate 110 of the positive electrode plate 110 is stacked with the electrode tab 120 of the other positive electrode plate to form the positive electrode tab of the electrode assembly, and the electrode tab 120 of the negative electrode plate of the electrode plate 110 is different. The electrode tab 120 of the negative electrode plate is stacked to form the negative electrode tab of the electrode assembly.

Referring to FIG. 2, the cutting part 130 has a length of the electrode sheet 100 on the upper side 100a and the lower side 100b of the electrode sheet 100 to separate the electrode plate 110. The pair is formed to be symmetrical with respect to the direction. The cutting parts 130 formed to correspond to each other on the upper side 100a and the lower side 100b are formed at regular intervals along the longitudinal direction of the electrode sheet 100.

The cutting part 130 may include a pair of first inclination parts 131 and a second inclination part 132. The pair of first inclined portion 131 and the second inclined portion 132 may be formed to be symmetric with respect to the direction CL in which the electrode sheet 100 is cut. The first inclined portion 131 extends from the upper side 100a and the lower side 100b of the electrode sheet 100 to the inside of the electrode sheet 100 and is inclined in a direction facing each other. In addition, the second inclined portion 132 extends from the end of the first inclined portion 131 to the inside of the electrode sheet 100 so as to be inclined in a direction facing each other. That is, the first angle θ11 of the first inclined portion 131 may be formed at an obtuse angle greater than 90 ° based on the direction CL in which the electrode sheet 100 is cut, and the electrode sheet 100 may be formed. The second angle θ12 of the second inclined portion 132 may also be formed at an obtuse angle greater than 90 ° based on the cutting direction CL. Therefore, one notch including the first inclined portion 131 and the second inclined portion 132 may be formed in the cutting portion 130. In addition, the first angle θ11 may be greater than the second angle θ12.

The portion cut by the cutting machine to separate the electrode plate 110 may be the second inclined portion 132. That is, it may be cut within the width W1 of the second inclined portion 132.

3, 4, and 5, the second inclined portion 132 of the cutting portion 130 may be cut along the line shown by ① to separate the electrode plate 110. The separated electrode plate 110 is formed in a rectangular shape having an upper side (first side), a lower side (second side), a right side (third side), and a left side (fourth side), and an upper side. And a first connection portion 150 is formed at the connection portion where the lower side and the right side meet, and a second connection portion 160 is formed at the connection portion where the upper side and the lower side and the left side meet. If the second inclined portion 132 of the cutting portion 130 is cut along the line shown by ① to separate the electrode plate 110, the first connection portion 150 is formed at the upper side (or lower side). Start to the right side, and are formed recessed in the inner side of the pole plate, and include two inclined portions (the first inclined portion 131 and the second inclined portion 132) forming an obtuse angle with respect to the right side. do. The first inclined portion 131 may be formed to be inclined to extend inwardly of the pole plate 110 starting from an upper side or a lower side according to the shape of the cutting unit 130 of the electrode sheet 100 before being cut. The second inclined portion 132 is formed to be inclined in the inward direction of the electrode plate 110 starting from the end of the first inclined portion 131. The first connection part 150 of the separated pole plate 110 may be made of a part of the first inclination part 131 and the second inclination part 132, and an angle thereof may be a second angle θ12. If the first inclined portion 131 of the cutting portion 130 is cut along the line shown by ② to separate the electrode plate 110, the first connection portion 150 is formed at the upper side (or lower side). It starts and continues to the right side, it is formed recessed in the inner side of the pole plate, and includes two inclined portions (first inclined portion 131) forming an obtuse angle with respect to the right side. In addition, even when the first inclined portion 131 is cut along the line shown by ② due to an error of the cutting machine, the first connection portion 150 of the separated pole plate 110 may be formed in the first inclined portion 131. The angle may be formed as a part of the first angle θ11. That is, the angle at the rightmost end of the first corner unit 150 may be an obtuse angle. Therefore, when passing through the roller 20 for laminating after the pole plate 110 is laminated, the impact transmitted from the roller 20 can be reduced.

On the other hand, the second connecting portion 160 of the separated pole plate 110, as well as the first inclined portion 131 and the second inclined portion 132, and other paired with the second inclined portion 132 Further including a part of the two inclined portion 132, the third angle θ13 of the second connecting portion 160 may be an acute angle. However, even when the third angle θ13 of the second connecting portion 160 is an acute angle, the second connecting portion 160 passes through the roller 20 for laminating after the pole plates 110 are stacked as described below. ), Since the pressure received by the roller 20 is small, the probability that the active material 11 is dropped from the electrode plate 110 is small.

Figure 6 shows that the active material is coated on the electrode plate according to an embodiment of the present invention is introduced between the rollers. 7 illustrates that the active material is coated on the electrode plate according to an embodiment of the present invention and passed through a roller.

6 and 7, the insulating layer 12 may be further stacked on the upper and lower portions of the electrode plate 110 coated with the active material 11 on the upper or lower portion. The insulating layer 12 may be an insulating tape or a separator.

The pole plate 110 is introduced between the pair of rollers 20 to laminate. Therefore, the insulating layer 12 is pressed when the electrode plate 110 is inserted between the rollers 20.

In addition, the active material 11 may be formed between the rollers 20 for the compression of the active material 11 in the exposed state formed on the electrode plate 110 without a separate insulating layer 12.

The active material 11 may be removed by being pressed by the roller 20 when the electrode plate 110 is inserted between the rollers 20. When the angle at the rightmost end of the first connecting portion 150 of the electrode plate 110 positioned at the front end introduced into the roller 20 is an acute angle, the force applied to the electrode plate 110 becomes greater, so that the active material The likelihood of dropping 11 from the electrode plate 110 becomes large. When the angle of the first connection portion 150 of the pole plate 110 according to the present invention is the second angle θ12, the angle of the first connection portion 150 of the pole plate 110 may be an obtuse angle. Therefore, when the electrode plate 110 is inserted between the rollers 20, the pressure applied to the electrode plate 110 is reduced, so that the probability of the active material 11 falling off is reduced.

On the other hand, since the second connecting portion 160 of the electrode plate 110 is a part which escapes between the rollers 20 when the second connecting portion 160 is introduced between the rollers 20, as compared with the first connecting portion 150. The pressure received by the roller 20 is small. Therefore, even if the angle of the second connector 160 corresponds to an acute angle, the probability that the active material 11 is dropped from the electrode plate 110 is small.

8 is a plan view of an electrode sheet according to another embodiment of the present invention. 9 is an enlarged view of a portion C of FIG. 8. 10 is a plan view of an electrode plate formed by cutting an electrode sheet according to another exemplary embodiment of the present invention. FIG. 11 is an enlarged view of portion D of FIG. 10. FIG. 12 is an enlarged view of a portion D ′ of FIG. 10.

Referring to FIG. 8, the electrode sheet 200 according to another embodiment of the present invention may include a pole plate 110, an electrode tab 120, and a cutting unit 230. The same components and the same parts as those of the previous embodiment are denoted by the same reference numerals, and the following description will be mainly given of differences.

Referring to FIG. 9, the cutting part 230 has a length of the electrode sheet 200 on the upper side 100a and the lower side 100b of the electrode sheet 200 to separate the electrode plate 110. The pair is formed to be symmetrical with respect to the direction. The cutting parts 230 formed to correspond to each other on the upper side 100a and the lower side 100b are formed at regular intervals along the longitudinal direction of the electrode sheet 200.

The cutting part 230 may include a pair of first inclination parts 231, a second inclination part 232, and a third inclination part 233. The pair of first slopes 231, the second slopes 232, and the third slopes 233 may be formed to be symmetrical with respect to the direction CL in which the electrode sheet 200 is cut. . The first inclined portion 231 extends from the upper side 100a and the lower side 100b of the electrode sheet 200 to the inside of the electrode sheet 200, and is formed to be inclined in a direction facing each other. The second inclined portion 232 extends from the end of the first inclined portion 231 to the inside of the electrode sheet 200 to be inclined in a direction facing each other. In addition, the third inclined portion 233 extends from the end of the second inclined portion 232 to the outside of the electrode sheet 200, and is formed to be inclined in a direction facing each other. Therefore, two notches including the first inclined portion 231, the second inclined portion 232, and the third inclined portion 233 may be formed. Here, the first angle θ21 of the first inclined portion 231 may be formed at an obtuse angle greater than 90 ° based on the direction CL in which the electrode sheet 200 is cut, and the electrode sheet 200 may be formed. The second angle θ22 of the second inclined portion 232 may also be formed at an obtuse angle greater than 90 ° based on the direction CL is cut. In addition, the third angle θ23 of the third inclined portion 233 may be formed at an acute angle greater than 45 ° based on the direction CL in which the electrode sheet 200 is cut. In addition, the first angle θ21 may be greater than the second angle θ22. Therefore, since two notches formed of the first inclined portion 231, the second inclined portion 232, and the third inclined portion 233 are formed in the cutting portion 230, the first connection portion of the electrode plate 110 may be formed. The probability at the rightmost end of 250) is obtuse.

Portions cut by the cutting machine to separate the electrode plate 110 may be the second inclined portion 232 and the third inclined portion 233. That is, the second inclined portion 232 and the third inclined portion 233 may be cut within the width (W2) formed.

10, 11, and 12, the electrode plate 200 formed by cutting the electrode sheet 200 has an upper side (first side), a lower side (second side), a right side (third side), and a left side. It is formed in a quadrangular shape having a side (fourth side), the first connecting portion 250 is formed in the connecting portion where the upper side and the lower side and the right side meet, the second side in the connecting portion where the upper side, the lower side and the left side meet The connection part 260 is formed. On the other hand, the second inclined portion 231 of the cutting portion 230 may be cut along the line shown by (3) to separate the electrode plate 110. If the second inclined portion 232 of the cutting portion 230 is cut along the line indicated by ③ to separate the electrode plate 110, the first connection portion 250 is disposed at the upper side (or lower side). Start to the right side, and are recessed in the inner side of the electrode plate, and include two inclined portions (the first inclined portion 231 and the second inclined portion 232) forming an obtuse angle with respect to the right side. do. According to the shape of the cutting part 230 of the electrode sheet 200, the first inclined part 231 is formed to be inclined to extend inwardly of the pole plate 110 starting from an upper side or a lower side. The second inclined portion 232 is formed to be inclined in the inward direction of the electrode plate 110 starting from the end of the first inclined portion 231. In this case, the first connection part 250 of the separated pole plate 110 may be made of a part of the first inclination part 231 and the second inclination part 232, and the angle may be the second angle θ22. In addition, even when the first inclined portion 231 is cut along the line shown by ④ due to an error of the cutting machine, the first connecting portion 250 of the separated pole plate 110 is part of the first inclined portion 231. The angle may be the first angle θ21. That is, when the first inclined portion 231 of the cutting portion 230 is cut along the line shown by ④ to separate the electrode plate 110, the first connection portion 250 has an upper side (or a lower side). Starting from and continuing to the right side, it is formed recessed in the inner side of the pole plate, and includes one inclined portion (first inclined portion 231) forming an obtuse angle with respect to the right side. In this case, the angle at the rightmost end of the first connector 250 may be an obtuse angle. Therefore, when passing through the roller 20 for laminating after the pole plate 110 is laminated, the impact transmitted from the roller 20 can be reduced.

On the other hand, when the pole plate 110 is separated by cutting the third inclined portion 233 of the cutting portion 230 shown in ⑤, the first connecting portion 250 is the third inclined portion 233 The angle may further include a part of) and may be the third angle θ23. That is, when the third inclined portion 233 of the cutting portion 230 is cut along the line shown by ⑤ to separate the electrode plate 110, the first connection portion 250 has an upper side (or a lower side). Inclined portions (first inclined portion 231, second inclined portion 232, and third inclined portion, which are formed to be recessed toward the inner side of the electrode plate and form an obtuse angle with respect to the right side, starting from). (233)) three. At this time, the first inclined portion 231 is formed to be inclined to extend inwardly of the pole plate 110 starting from the upper side or the lower side, according to the shape of the cutting portion 230 of the electrode sheet 200 before being cut. The second inclined portion 232 is formed to be inclined in the inward direction of the electrode plate 110 starting from the end of the first inclined portion 231, and the third inclined portion 233 is formed at the end of the second inclined portion 232. Starting and extending in the outward direction of the electrode plate 110. In this case, the angle at the rightmost end of the first connector 250 may be an acute angle. Even if the first connection part 250 further includes a part of the third inclined part 233 so that the angle at the rightmost end thereof is an acute angle, the size of the angle may be 45 ° or more. However, since the first connection part 250 further includes a third inclination part 233, even when the angle is an acute angle, the size of the first connection part 250 is 45 ° or more, and thus the pressure applied to the electrode assembly by the roller 20. Since is not large, the probability that the active material 11 is dropped is not great.

In addition, the second connecting portion 260 of the separated pole plate 110 is not only the first inclined portion 231, the second inclined portion 232 and the third inclined portion 233, but also the third inclined portion ( The fourth angle θ24 of the second connector 260 may be an acute angle, further including a portion of another third inclined portion 233 paired with 233. However, even when the angle of the second connector 260 is an acute angle, when passing through the roller 20 for laminating after the pole plate 110 is stacked as described above, the second connector 260 is the roller ( Since the pressure received by 20) is small, the probability that the active material 11 is dropped from the electrode plate 110 is small.

Therefore, the cutting part 230 further includes the third inclined part 233 so that two notches are formed, so that when the cutting part 230 is cut, the first connection part 250 of the electrode plate 110 is cut. The probability that the rightmost edge of is an obtuse angle may be higher than when one notch is formed.

13 is a plan view of an electrode sheet according to another embodiment of the present invention. FIG. 14 is an enlarged view of portion E of FIG. 13. FIG. 15 is an enlarged view of a portion F of FIG. 13. 16 is a plan view of an electrode plate formed by cutting an electrode sheet according to still another exemplary embodiment of the present invention. FIG. 17 is an enlarged view of a portion G of FIG. 16. FIG. 18 is an enlarged view of a portion G ′ of FIG. 16. 19 is an enlarged view of a portion H of FIG. 16. 20 is an enlarged view of a portion 'H' of FIG. 16.

Referring to FIG. 13, the electrode sheet 300 according to another embodiment of the present invention may include a pole plate 110, an electrode tab 120, a first cutting portion 230, and a second cutting portion 340. Can be. The same components and the same parts as those of the previous embodiment are denoted by the same reference numerals, and the following description will be mainly given of differences.

13, 14, and 15, the second cutting part 340 may be disposed on the lower side 300b of the electrode sheet 300 to separate the electrode plate 110. 230 is formed at a position symmetrical with respect to the longitudinal direction of the electrode sheet 300. The second cutting parts 340 formed on the lower side 300b to correspond to the first cutting parts 230 are formed at regular intervals along the length direction of the electrode sheet 200.

The lower end 300b includes a parallel portion 301b parallel to the upper side 100a and a curved portion 302b extending from the parallel portion 301b to the inside of the electrode sheet 300. Therefore, the probability that the angle at the rightmost end of the third connector 370 of the electrode plate 110 is an obtuse angle is increased.

The second cutting portion 340 may include a pair of inclined portions 341. The pair of inclined portions 341 may be formed to be symmetrical with respect to the direction CL in which the electrode sheet 300 is cut. The inclined portion 341 extends from the curved surface portion 302b of the lower side 300b of the electrode sheet 300 to the inside of the electrode sheet 300 and is formed to be inclined in a direction facing each other. That is, the fifth angle θ35 of the inclined portion 341 may be formed at an obtuse angle greater than 90 ° based on the direction CL in which the electrode sheet 300 is cut. Therefore, one notch made of the inclined portion 341 may be formed in the second cutting portion 340.

The portion cut by the cutting machine to separate the electrode plate 110 is the second inclined portion 232 and the third inclined portion 233 and the second cutting portion 340 of the first cutting portion 230. The inclined portion 341 may be. That is, within a width W3 formed by the second inclined portion 232 and the third inclined portion 233 of the first cutting portion 230 and the inclined portion 341 of the second cutting portion 340. Can be cut.

16 to 20, the electrode plate 300 formed by cutting the electrode sheet 300 has an upper side (first side), a lower side (second side), a right side (third side), and a left side (first). 4 sides) is formed in a rectangular shape, the first side connection portion where the upper side and the right side meets the first connection portion 250, the second side connection portion 260, the lower side and the right side meet the connecting portion where the upper side and the left side meet In the connecting portion, a fourth connecting portion 380 is formed at the third connecting portion 370 and the connecting portion where the lower side and the left side meet. The pole plate 110 may be separated by cutting a line ⑥ of the second inclined portion 232 of the first cutting portion 230 and the inclined portion 341 of the second cutting portion 340. If the second inclined portion 232 of the first cutting portion 230 and the inclined portion 341 of the second cutting portion 340 is cut along the line shown by ⑥ to separate the pole plate 110, The first connection part 250 is formed starting from the upper side and extending to the right side, and is formed by being recessed in the inner side of the pole plate and forming an obtuse angle with respect to the right side (first inclined portion 231 and second). 3, the third connection portion 370 extends from the lower side to the right side and extends to the inner side of the pole plate to form an obtuse angle with respect to the right side. ). The first inclined portion 231 starts from an upper side of the electrode sheet 300 in the inner direction of the electrode plate 110 according to the shape of the first cut portion 230 and the second cut portion 340 before being cut. It is extended and formed to be inclined, the second inclined portion 232 is formed to be inclined in the inward direction of the pole plate 110 starting from the end of the first inclined portion 231, the inclined portion 341 is at the curved end of the lower side It is formed to be inclined inwardly of the electrode plate. Accordingly, the first connection part 250 of the separated pole plate 110 may be formed as part of the first inclination part 231 and the second inclination part 232 to be the second angle θ22, and the third connection part. 370 may be made of an inclined portion 341 and may have a fifth angle θ35. Also, the first inclined portion 231 may be cut along the line ⑦ due to an error of the cutting machine. If the first inclined portion 231 of the first cutting portion 230 and the inclined portion 341 of the second cutting portion 340 is cut along the line shown by ⑦ to separate the pole plate 110, The first connection part 250 starts from the upper side and continues to the right side, and is formed by being recessed in the inner side of the pole plate, and forms an obtuse portion (first inclined portion 231) that forms an obtuse angle with respect to the right side. The third connection part 370 includes the inclined portion 341 extending from the lower side to the right side and extending toward the inner side of the pole plate to form an obtuse angle with respect to the right side. Even in this case, the first connection part 250 of the separately charged electrode plate 110 may be made of a part of the first inclination part 231 to be a first angle θ21, and the third connection part 370 may be The lower surface portion 300b may be formed as a part of the curved portion 302b to have a round shape. That is, the angle at the rightmost end of the first connector 250 and the third connector 370 may be an obtuse angle. Therefore, when passing through the roller 20 for laminating after the pole plate 110 is laminated, the impact transmitted from the roller 20 can be reduced.

When the third inclined portion 233 of the first cutting portion 230 and the inclined portion 341 of the second cutting portion 340 are cut along the line shown by ⑧ to separate the electrode plate 110, The first connection part 250 is formed by inclining the inner side of the pole plate, starting from the upper side to the right side, and forming an obtuse angle with respect to the right side (the first inclined portion 231 and the second inclined portion). The third portion 232 and the third inclined portion 233) is included, and the third connecting portion 370 starts from the lower side and continues to the right side, and extends to the inner side of the pole plate based on the right side. It includes an inclined portion 341 forming an obtuse angle. The first inclined portion 231 starts from an upper side of the electrode sheet 300 in the inner direction of the electrode plate 110 according to the shape of the first cut portion 230 and the second cut portion 340 before being cut. It is extended and formed to be inclined, the second inclined portion 232 is formed to be inclined in the inward direction of the electrode plate 110 starting from the end of the first inclined portion 231, the third inclined portion 233 is the second inclined portion The inclined portion 341 is formed to be inclined in the outward direction of the pole plate 110 starting from the end of the 232, and is inclined in the inward direction of the pole plate, starting at the curved end of the lower side. When the pole plate 110 is separated by cutting the line shown as ⑧ between the third inclined portion 233 and the inclined portion 341 of the second cutting portion 340 of the first cutting portion 230, The first connector 250 may further include a portion of the third inclined portion 233, and an angle thereof may be a third angle θ23. That is, the angle at the rightmost end of the first connector 250 may be an acute angle. Even if the first connector 250 includes a portion of the third inclined portion 233 and the angle is an acute angle, the angle may be greater than or equal to 45 °. However, since the first connection part 250 further includes a third inclination part 233, even when the angle is an acute angle, the size of the first connection part 250 is 45 ° or more, and thus the pressure applied to the electrode assembly by the roller 20. Since is not large, the probability that the active material 11 is dropped is not great.

On the other hand, the second connecting portion 260 of the separated pole plate 110, as well as the first inclined portion 231, the second inclined portion 232 and the third inclined portion 233, the third inclined portion ( The fourth angle θ24 of the second connector 260 may be an acute angle, further including a portion of another third inclined portion 233 paired with 233. In addition, the fourth connection portion 380 of the separated pole plate 110 further includes not only the inclined portion 341 but also a portion of another inclined portion 341 paired with the inclined portion 341. The sixth angle θ36 of the fourth connector 380 may be an acute angle. However, even when the angle of the second connecting portion 260 and the fourth connecting portion 380 is an acute angle, when passing through the roller 20 for laminating after the pole plate 110 is stacked as described above, the second connecting portion Since the pressure received by the roller 20 of the 260 and the fourth connector 380 is small, the probability of the active material 11 falling off from the electrode plate 110 is small.

Therefore, the shape of the first cutting portion 230 and the second cutting portion 340 may be formed differently, and the second cutting portion 340 is formed to extend from the curved portion of the lower portion 300b The second connection portion 360 of the electrode plate 110 may have a higher probability of forming an obtuse angle.

Meanwhile, the first cutting part 230 and the second cutting part 340 may be formed differently from each other as well as the shape of another embodiment.

21 is a plan view of an electrode sheet according to another embodiment of the present invention. FIG. 22 is an enlarged view of a portion G of FIG. 21. 23 is a plan view of an electrode plate formed by cutting an electrode sheet according to still another exemplary embodiment of the present invention. 24 is an enlarged view of a portion H of FIG. 23. FIG. 25 is an enlarged view of a portion 'H' of FIG. 23.

Referring to FIG. 21, an electrode sheet 400 according to another exemplary embodiment of the present invention may include a pole plate 110, an electrode tab 120, and a cutting unit 430. The same components and the same parts as those of the previous embodiment are denoted by the same reference numerals, and the following description will be mainly given of differences.

Referring to FIG. 22, the cutting part 430 has a length of the electrode sheet 400 on the upper side 100a and the lower side 100b of the electrode sheet 400 to separate the electrode plate 110. The pair is formed to be symmetrical with respect to the direction. The cutting parts 430 formed to correspond to each other on the upper side 100a and the lower side 100b are formed at regular intervals along the length direction of the electrode sheet 400.

The cutting part 430 may include a first inclined part 431, a second inclined part 432, and a third inclined part 433. The first inclined portion 431 extends from the upper side 100a and the lower side 100b of the electrode sheet 400 to the inside of the electrode sheet 400 to be inclined. The second inclined portion 432 extends from the end of the first inclined portion 431 to the inside of the electrode sheet 400 to be inclined. In addition, the third inclined portion 433 extends from the upper side 100a and the lower side 100b of the electrode sheet 400 to the inner side of the electrode sheet 400, and thus the first inclined portion 431 and It is formed to be inclined in a direction facing the second inclined portion 432. That is, the first angle θ41 of the first inclined portion 431 may be formed at an obtuse angle greater than 90 ° based on the direction CL in which the electrode sheet 400 is cut, and the electrode sheet 400 may be formed. The second angle θ42 of the second inclined portion 432 may also be formed at an obtuse angle greater than 90 ° based on the direction CL of which is cut. In addition, the third angle θ43 of the third inclined portion 433 may be an acute angle based on the direction CL in which the electrode sheet 400 is cut. In addition, the first angle θ41 may be greater than the second angle θ42. Accordingly, the cutout 430 may be formed with one notch including the first inclined portion 431, the second inclined portion 432, and the third inclined portion 433, but the cut portion 430 may be formed. Since is formed to be asymmetrical with respect to the center of the cutting portion 430, if the cutting is made within the width (W4) of the second inclined portion 432 of the first connecting portion 450 of the pole plate 110 The angle at the rightmost end may be an obtuse angle. Meanwhile, the center of the cutting part 430 means the center of the cutting part 430 based on the width of the first inclined part 431, the second inclined part 432, and the third inclined part 433.

The portion cut by the cutting machine to separate the electrode plate 110 may be the second inclined portion 432. That is, it may be cut within the width W4 of the second inclined portion 432.

Referring to FIGS. 23, 24, and 25, the electrode plate 400 formed by cutting the electrode sheet 400 may have an upper side (first side), a lower side (second side), a right side (third side), and a left side. It is formed in a quadrangular shape having a side (fourth side), the first connecting portion 450 is formed in the connecting portion where the upper side and the lower side and the right side meet, and the connecting portion where the upper side and the lower side and the left side meet 2 connection portion 460 is formed. The pole plate 110 may be separated by cutting the second inclined portion 432 of the cutting portion 430 along the line ⑨. If the second inclined portion 432 of the cutting portion 430 is cut along the line indicated by ⑨ to separate the electrode plate 110, the first connecting portion 450 starts from the upper side and moves to the right side. Subsequently, it is formed to be recessed toward the inner side of the pole plate, and includes two inclined portions (the first inclined portion 431 and the second inclined portion 432) that form an obtuse angle with respect to the right side. The first inclined portion 431 may be formed to be inclined to extend inwardly of the pole plate 110 starting from an upper side or a lower side according to the shape of the cutting portion 430 of the electrode sheet 400 before being cut. The second inclined portion 432 is formed to be inclined in the inward direction of the electrode plate 110 starting from the end of the first inclined portion 431. Therefore, the first connection part 450 of the separated pole plate 110 may be made of a part of the first inclination part 431 and the second inclination part 432, and the angle may be the second angle θ42. In addition, the first inclined portion 431 may be cut along the line shown by 로 due to an error of the cutting machine. If the first inclined portion 431 of the cutting portion 430 is cut along the line shown by ⑩ to separate the electrode plate 110, the first connecting portion 450 starts at the upper side and moves to the right side. Subsequently, it is formed to be recessed toward the inner side of the pole plate, and includes one inclined portion (first inclined portion 431) that forms an obtuse angle with respect to the right side. Even in this case, the angle is made of a part of the first connection portion 450 of the separated electrode plate 110 may be the first angle θ41. That is, the angle at the rightmost end of the first connector 45 may be an obtuse angle. Therefore, when passing through the roller 20 for laminating after the pole plate 110 is laminated, the impact transmitted from the roller 20 can be reduced.

On the other hand, the electrode plate 110 may be separated by cutting the line shown by the third inclined portion 433 due to the error of the cutting machine. In this way, when the third inclined portion 433 of the cutting portion 430 is cut along the line shown by ⑪ to separate the electrode plate 110, the first connection portion 450 starts at the upper side and moves to the right side. Subsequently, the inclined portions (the first inclined portion 431, the second inclined portion 432 and the third inclined portion 433) formed by being recessed in the inner side of the pole plate and forming an obtuse angle with respect to the right side are 3 Will be included. In this case, the first inclined portion 431 may be formed to be inclined by extending from the upper side or the lower side to the inner side of the electrode plate 110 according to the shape of the cutting portion 430 of the electrode sheet 400 before being cut. The second inclined portion 432 is formed to be inclined in the inward direction of the electrode plate 110 starting from the end of the first inclined portion 431, and the third inclined portion 433 is formed at the end of the second inclined portion 432. Starting and extending in the outward direction of the electrode plate 110. When the third inclined portion 433 is cut along the line shown by ⑪, the first connection portion 450 further includes a part of the third inclined portion 433, and the angle thereof is the third angle θ43. May be). That is, the angle at the rightmost end of the first connector 450 may be an acute angle. However, if the ratio of the width formed by the first inclined portion 431 and the second inclined portion 432 is increased from the width formed by the cutting portion 430, the maximum of the first connection portion 450 of the pole plate 110 is increased. The probability that the angle at the right end is an obtuse angle may increase.

In addition, the second connection part 460 of the separated pole plate 110 further includes a part of the second inclination part 432 as well as the third inclination part 433. The fourth angle θ44 may be an acute angle. However, even when the fourth angle θ44 of the second connector 46 is an acute angle, as described above, when the electrode plate 110 is laminated, the second connector 460 passes through the roller 20 for laminating. ), Since the pressure received by the roller 20 is small, the probability that the active material 11 is dropped from the electrode plate 110 is small.

Therefore, the cutting part 460 is the first inclined portion 431, the second inclined portion 432 and the third inclined portion 433 is made asymmetrical, when cutting the cutting portion 460 The probability that the angle of the rightmost end of the first connector 460 of the electrode plate 110 is an obtuse angle may be higher than when the symmetry is formed.

What has been described above is just one embodiment for carrying out the electrode sheet according to the present invention, the electrode plate produced by cutting the electrode sheet, the electrode assembly formed by stacking the electrode plate and the method for producing the electrode plate, the present invention The present invention is not limited to the above-described embodiments, and any one of ordinary skill in the art to which the present invention pertains can make various changes without departing from the gist of the present invention as claimed in the following claims. It will be said that there is a technical spirit of the present invention.

[Description of the code]

11 active material 12 insulating layer

20: roller 100,200,300,400: electrode sheet

100a: upper side 100b, 300b: lower side

110: electrode plate 120: electrode tab

130,230,340,430: Cutting part 150,250,450: First connection part

160,260,460: second connection portion 370: third connection portion

380: fourth connection

Claims (10)

An electrode active material is coated on one side or both sides, and a first side and a second side facing the first side, a third side perpendicular to the first side and the second side, and a fourth side opposite to the third side. In a secondary battery comprising a pole plate having a side, At least one connecting portion formed at the connecting portion of the first side and the third or fourth side, or the connecting portion of the second side and the third or fourth side, wherein the connecting portion is formed at the first side. Starting from the third side or the fourth side or starting from the second side to the third side or the fourth side and recessed in the inward direction of the electrode plate. A secondary battery comprising two or more inclined portions forming obtuse angles based on four sides. The method of claim 1, The inclined portion A first inclined portion extending from an at least one of the first side and the second side to be inclined in an inward direction of the electrode plate; And Secondary battery including a second inclined portion formed to be inclined extending from the end of the first inclined portion in the inner direction of the electrode plate. The method of claim 2. A secondary battery having a first angle formed by the first inclined portion based on the third side or the fourth side is larger than a second angle formed by a second inclined portion. The method of claim 1, The inclined portion A first inclined portion extending from an at least one of the first side and the second side to be inclined in an inward direction of the electrode plate; And A second inclined portion formed at an end of the first inclined portion and extending in an inward direction of the electrode plate to be inclined; The secondary battery further comprises a third inclined portion formed at an acute angle with respect to the third side or the fourth side and extending in an outward direction of the pole plate starting from the end of the second slope. The method of claim 4, wherein A secondary battery having an angle of 45 ° or more formed by the third inclined portion with respect to the third side or the fourth side. The method of claim 1, The connection part includes a first connection part formed on the first side and a second connection part formed on the second side, The second side of the pole plate includes a parallel portion parallel to the first side and a curved portion extending from the end of the parallel portion in an inward direction of the pole plate, wherein the inclined portion of the second connection portion formed on the second side is Starting from the end of the curved portion of the secondary battery formed in the direction extending in the direction of the electrode plate. The method of claim 6, The inclined portion of the second connecting portion formed on the second side of the electrode plate includes a inclined portion formed inclined to extend in the inward direction of the electrode plate starting from the second side. The method of claim 7, wherein The inclined portion of the first connecting portion formed on the first side of the pole plate A first inclined portion starting from the first side and extending in an inward direction of the electrode plate to be inclined; And A second inclined portion formed at an end of the first inclined portion and extending in an inward direction of the electrode plate to be inclined; The secondary battery further comprises a third inclined portion formed at an acute angle with respect to the third side or the fourth side and extending in an outward direction of the pole plate starting from the end of the second inclined portion. The method of claim 1, The inclined portion further includes at least one inclined portion which forms an acute angle with respect to the third or fourth side. The method of claim 9, The inclined portion A first inclined portion extending from an at least one of the first side and the second side to be inclined in an inward direction of the electrode plate; A second inclined portion starting at the end of the first inclined portion and extending in an inward direction of the electrode plate to be inclined; And A secondary battery comprising a third inclined portion starting from at least one of the first side and the second side and extending inwardly of the electrode plate, the third inclined portion inclined in a direction facing the first inclined portion and the second inclined portion.

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