JPWO2013141279A1 - Square non-aqueous electrolyte storage cell electrode plate - Google Patents

Abstract

Provided is an electrode plate for a rectangular nonaqueous electrolyte storage cell that can prevent occurrence of a short circuit inside a container and is easy to process. At least the first corner portion 11 and the second corner portion of the electrode plate 1 for the square nonaqueous electrolyte storage cell having the first side 3, the second side 5, the third side 7, and the fourth side 9. A first bending portion 21 and a second bending portion 23 are formed in the corner portion 13. The first bending portion 21 forms an acute angle θ11 between the first side 3 and the tangent line 22A of the first bending portion 21 at the contact 21A of the first bending portion 21 and the first extension line 3 ′. It is formed to do. The first bending portion 21 has an acute angle θ12 between the second side 5 and the tangent line 22B of the first bending portion 21 at the contact 21B of the first bending portion and the second extension line 5 ′. Is formed. The second curved portion 23 is formed in the same manner.

Description

  The present invention relates to an electrode plate for a prismatic non-aqueous electrolyte storage cell.

  The prismatic nonaqueous electrolyte storage cell forms an electrode plate group by alternately laminating positive and negative electrode plates with separators interposed therebetween. As the positive electrode plate and the negative electrode plate (hereinafter referred to as “electrode plate” when collectively referred to), it is common to use a rectangular plate having ears, but it is inserted into a rectangular container of a storage cell. When doing so, the corners may break, causing internal short circuit. Therefore, as disclosed in Japanese Patent Laid-Open No. 9-82361 (Patent Document 1), at least both corners of the electrode plate positioned on the side first inserted into the rectangular container are circular arcs for the purpose of preventing a short circuit inside the storage cell. Some have a shape.

Japanese Patent Laid-Open No. 9-82361

  However, machining the corners of the electrode plate into an arc shape disclosed in Japanese Patent Laid-Open No. 9-82361 (Patent Document 1) requires high machining accuracy. This is because, as shown in FIG. 4 of Japanese Patent Application Laid-Open No. 9-82361 (Patent Document 1), in order to make the corner portion into an arc, the corner portion of the electrode plate is cut using an arc-shaped cutting blade. Although it is necessary, if the cutting blade is cut with a slight deviation at the time of cutting, a small corner as shown in FIG. 11, that is, a so-called “burr” is generated. This is because the corner shown in FIG. 4 of Japanese Patent Laid-Open No. 9-82361 (Patent Document 1) has an arc shape in which the center angle of the arc is 90 °, and therefore a perpendicular line extending from the center point O to one side of the electrode plate. This is because the tangent line of the arc at the crossing point and one side of the electrode plate are parallel (overlapping). When using a plate with burrs, not only can the burr penetrate the separator and contact the adjacent plate, but a short circuit may occur directly. It is also a cause of causing dendrites that cause the occurrence of

  An object of the present invention is to provide an electrode plate for a rectangular nonaqueous electrolyte storage cell that can prevent the occurrence of a short circuit inside the container and is easy to process.

  The electrode plate for a rectangular non-aqueous electrolyte storage cell according to the present invention has a side located on the bottom side of the battery container as a first side, and a side connected to one end of the first side via the first corner. 2 side, the side facing the second side and connected to the other end of the first side via the second corner, the third side, the side having the ear portion and facing the first side Let it be the fourth side. The first corner portion is constituted by a first curved portion that is convex toward a point where the first extension line of the first side and the second extension line of the second side intersect, The corner portion is configured by a second curved portion that protrudes toward a point where the first extension line and the third extension line of the third side intersect. Then, an acute angle is formed between the first curved portion and the tangent line of the first curved portion at the contact point between the first side and the first curved portion, greater than 0 ° and smaller than 45 ° between the first extension line. And an acute angle greater than 0 ° and less than 45 ° is formed between the tangent line of the first curved portion at the contact point of the second side and the first curved portion and the second extension line. To form. Further, the second bending portion is formed with an acute angle greater than 0 ° and less than 45 ° between the tangent line of the second bending portion at the contact point between the first side and the second bending portion and the first extension line. And an acute angle greater than 0 ° and less than 45 ° is formed between the tangent line of the second curved portion at the contact point of the third side and the second curved portion and the third extension line. To form. When the first and second curved portions having such shapes are formed, the cutting blades also have shapes that match the respective curved portions, and the cutting blades for processing the corners are slightly displaced from the predetermined positions. Even if this is the case, there is no possibility of generating a small corner portion that becomes a burr at the boundary portion between the curved portion and the side. Therefore, according to the present invention, it is possible to easily form a curved portion at the corner of the electrode plate without requiring high processing accuracy, and to short-circuit inside the storage cell at the contact point between the side and the curved portion. There is an effect of not forming a new corner portion that causes the above.

  One end of the fourth side and the second side are connected via a third corner, and the other end of the fourth side and the third side are connected via a fourth corner. In some cases, the third corner and the fourth corner can also cause a short circuit inside the container. Therefore, in this case, it is preferable to form curved portions at the third corner and the fourth corner. In this case, like the first and second curved portions, the third corner portion is convex toward the point where the fourth extension line and the second extension line of the fourth side intersect. The fourth curved portion is constituted by the third curved portion, and the fourth corner portion is constituted by a fourth curved portion that is convex toward a point where the fourth extended line and the third extended line of the third side intersect. To do. Then, the third bending portion is formed with an acute angle greater than 0 ° and less than 45 ° between the tangent line of the third bending portion at the contact point of the fourth side and the third bending portion and the fourth extension line. And an acute angle greater than 0 ° and less than 45 ° is formed between the tangent line of the third curved portion at the contact point of the second side and the third curved portion and the second extended line. To form. The fourth bending portion also forms an acute angle between the fourth side and the fourth bending portion at the contact point between the fourth side and the fourth bending portion between the fourth extension line and the fourth extension line. And an acute angle greater than 0 ° and less than 45 ° is formed between the tangent line of the fourth curved portion at the contact point of the third side and the fourth curved portion with the third extension line. To form.

  When one end of the fourth side and the second side are connected by the third corner, and the ear is provided on the fourth side so that one side of the ear is continuous with the third side Similarly, it is preferable to form a curved portion at the third corner. The third corner provided in this case is constituted by a third curved portion that is convex toward the point where the fourth extension line and the second extension line of the fourth side intersect, The bending portion is formed so that an tangent line of the third bending portion at a contact point between the fourth side and the third bending portion forms an acute angle between 0 ° and 45 ° between the fourth extension line. And the tangent of the 3rd curved part in the contact of a 2nd edge | side and a 3rd curved part forms so that the acute angle larger than 0 degree and smaller than 45 degrees may form between 2nd extension lines.

  By processing the third and / or fourth corners in this way, the corners of the electrode plate can be easily processed, and a short circuit inside the container can be prevented.

  In addition, when an electrical storage cell discharges, it is known that an electric current will flow in an ear | edge part through the shortest conductive path in an electrode plate will contribute to the improvement of discharge efficiency. Therefore, it is preferable not to increase the length of the conductive path to the ear. Therefore, when there is a third corner and a fourth corner, the portions of the fourth side located on both sides of the ear are inclined so as to approach the first side as they move away from the ear. It is preferable to make it a shape. Further, when the ear is provided on the fourth side so that one side of the ear is continuous with the third side, the fourth side approaches the first side as the ear is away from the ear. It is sufficient to make it tilt like this. By doing in this way, it becomes possible for the electric current from each part of an electrode plate to reach an ear | edge part through the shortest conductive path, and can improve the discharge efficiency of an electric current.

  If the acute angle is greater than 0 ° and smaller than 45 °, the effect of the present invention can be obtained. For example, if the acute angle is larger than 15 ° and smaller than 40 °, the contact portion is formed while forming the curved portion at the corner portion of the electrode plate even when the cutting blade used for machining the corner portion is shifted from the side. This is practical because it does not form a new corner. For example, if the acute angle is larger than 2 ° and smaller than 15 °, the area of the electrode plate can be increased, and there is an effect that the performance of the storage cell is not deteriorated.

It is a figure which shows 1st Embodiment of the electrode plate for square non-aqueous electrolyte electrical storage cells of this invention. It is the schematic enlarged view which expanded and showed the area | region which attached | subjected the code | symbol A of FIG. It is a figure which shows an example of the cutting blade for cut | disconnecting a corner | angular part. (A) is a partially broken front view of a lithium ion secondary battery as a nonaqueous electrolyte battery provided with the electrode plate for a rectangular nonaqueous electrolyte storage cell according to the first embodiment of the present invention. (B) is a left side view, and (C) is a right side view. It is a figure which shows 2nd Embodiment of the electrode plate for square nonaqueous electrolyte electrical storage cells of this invention. It is a figure which shows 3rd Embodiment of the electrode plate for square non-aqueous electrolyte electrical storage cells of this invention. It is a figure which shows 4th Embodiment of the electrode plate for square non-aqueous electrolyte electrical storage cells of this invention. It is a figure which shows 5th Embodiment of the electrode plate for square non-aqueous electrolyte electrical storage cells of this invention. It is a figure which shows 6th Embodiment of the electrode plate for square nonaqueous electrolyte electrical storage cells of this invention, and shows the example which cut | disconnected the corner | angular part using the cutting blade of a shape different from 1st Embodiment. FIG. It is a figure which shows an example of the cutting blade used in 6th Embodiment. It is a figure which shows the example of the "burr" which generate | occur | produces when processing the electrode plate for square nonaqueous electrolyte storage cells by a prior art.

  Hereinafter, an example of an embodiment of an electrode plate for a rectangular nonaqueous electrolyte storage cell according to the present invention will be described with reference to the drawings.

[First Embodiment]
[Plate for rectangular non-aqueous electrolyte storage cell]
FIG. 1 is a front view of a positive electrode plate 1 according to an embodiment in which the electrode plate for a rectangular nonaqueous electrolyte storage cell of the present invention is applied to a positive electrode plate of a lithium ion secondary battery as a nonaqueous electrolyte battery. In the lithium ion battery using the positive electrode plate 1 of the present embodiment, since the negative electrode plate is larger than the positive electrode plate 1, a known electrode plate is used as the negative electrode plate for the purpose of preventing a short circuit of the electrode plate. Also good. Therefore, in the present embodiment, only the shape of the positive electrode plate 1 will be described.

  A positive electrode plate (a rectangular nonaqueous electrolyte storage cell electrode plate) 1 includes a first side 3, a second side 5, a third side 7, and a fourth side 9. A positive electrode current collector plate 10 made of an aluminum foil provided with current collecting ear portions 10B provided integrally with the current collector plate body 10A is provided. An active material layer 2 is formed on the positive electrode current collector plate 10. The active material layer 2 may be formed on both surfaces of the current collector plate body 10A, but the active material layer 2 is formed so as to leave a region along the fourth side 9 where the active material layer 2 is not formed. May be.

  1 is a first side 3 located on the bottom side of a battery container, which will be described later, and one end of the first side 3 and the first corner 11 are connected to each other. The side connected through the second side 5 is the second side 5, and the side connected to the other end of the first side 3 through the second corner 13 is the third side 7. The side facing the first side 3 and connected to the second side 5 via the third corner 15 and the third side 7 via the fourth corner 17 is the fourth side 9. It is. The fourth side 9 is provided with an ear portion 10B. In the present embodiment, since the ear portion 10B is provided on the fourth side 9 so as to be continuous with the third side 7, the fourth corner portion 17 does not appear as a corner portion.

  In the present embodiment, the first curved portion 21 is formed at the first corner portion 11 on the insertion side and the second curved portion 13 is formed at the second corner portion 13 when housed in a battery container described later. 23 is formed. The first curved portion 21 includes a first extension line 3 ′ (first line extending along the first side) of the first side and a second extension line 5 ′ (second line of the second side 5). (A virtual line extending along the side) is formed so as to protrude toward the point where it intersects. The second curved portion 23 includes a first extension line 3 ′ (virtual line extending along the first side) of the first side 3 and a third extension line 7 ′ (third line of the third side). A second curved portion 23 is formed which is convex toward a point where a virtual line extending along the side intersects.

  FIG. 2 is an enlarged view of the region denoted by reference symbol A in FIG. 1, and mainly shows an enlarged view of the first bending portion 21. In the present embodiment, since the first bending portion 21 and the second bending portion 23 are processed into the same shape, only the configuration of the first bending portion 21 will be described in detail here, and the second bending portion will be described. The description about 23 is omitted.

The first bending portion 21 has an acute angle θ ₁₁ between the first side 3 and the tangent line 22A of the first bending portion 21 at the contact 21A of the first bending portion 21 and the first extension line 3 ′. It is formed to form. Further, the first bending portion 21 has an acute angle θ ₁₂ between the second side 5 and the tangent line 22B of the first bending portion 21 at the contact 21B of the first bending portion and the second extension line 5 ′. Is formed. If the angles θ ₁₁ and θ ₁₂ are angles larger than 0 ° and smaller than 45 °, the effect of the present invention can be obtained. In addition, the angles θ ₁₁ and θ ₁₂ can be different from each other. In particular, when the angles θ ₁₁ and θ ₁₂ are greater than 2 ° and less than or equal to 15 °, the curved portion that can prevent the occurrence of burrs without significantly reducing the area of the electrode plate from a practical viewpoint. It is confirmed that it can be easily obtained. Therefore, in this embodiment, the angle θ ₁₁ = θ ₁₂ = 3 ° is formed.

FIG. 3 is a diagram illustrating an example of the cutting blade 25 used when the corner portion is cut by press working. The cutting blade 25 has a curved cutting blade portion 27 having the same shape as the contour of the first bending portion 21, and extends from the end 27A of the curved cutting blade portion 27 in the same direction as the tangent line 22A. The extended cutting blade portion 29B extends from the end portion 27B of the curved cutting blade portion 27 in the same direction as the tangent line 22B. If the angles θ ₁₁ and θ ₁₂ are increased, the curvature radius of the so-called curved portion is increased, so that the extended cutting blade portions 29A and 29B may be formed by extending the curved cutting blade portion 27 as it is. When such a cutting blade 25 is used, even if there is a slight misalignment between the electrode plate and the cutting blade during cutting, burrs are generated between the curved portion and the side of the electrode plate as in the conventional case. There is nothing.

  Such a cutting blade 25 has a shape that is not parallel to the first side 3 and the second side 5 at the contact points 21A and 21B, and extends in the direction of the tangents 22A and 22B or outside the tangent line. 11A and 29B extending in a direction away from the contact point, even if the cutting blade 25 is cut in a slightly deviated state, only the positions of the contacts 21A and 21B are shifted. No burr as shown in Fig. Therefore, with the electrode plate shape of the present embodiment, a rectangular non-aqueous electrolyte storage cell electrode plate that can be easily processed at the corners and can prevent occurrence of a short circuit inside the battery container. Can be obtained. The cutting blade that forms the second curved portion 23 has the same configuration, and the second curved portion 23 is formed by cutting the second corner portion 13 with the cutting blade 25.

  When cutting the first corner portion 11 of the electrode plate for the square non-aqueous electrolyte storage cell, the electrode plates for the square non-aqueous electrolyte storage cell having the unprocessed first corner portion 11 one by one or In a state where a plurality of sheets are stacked, the end portion 27A of the cutting blade 25 is aligned with a predetermined position on the first side 3, and the end portion 27B is aligned with a predetermined position on the second side 5, and the corner portion is pressed by pressing. Just cut it.

[Production of lithium ion secondary battery]
4A is a partially broken front view of the lithium ion secondary battery 31, FIG. 4B is a left side view, and FIG. 4C is a right side view. In the present embodiment, the thickness dimensions of some components are exaggerated for easy understanding. A lithium ion secondary battery is manufactured using the positive electrode plate 1 serving as the electrode plate for a rectangular non-aqueous electrolyte storage cell configured as described above and the negative electrode plate 32 having a known shape with no corners. did. The negative electrode plate 32 is formed larger than the positive electrode plate 1 so as to completely face the positive electrode plate 1. The lithium ion secondary battery 31 of the present embodiment includes an electrode plate group 33 and a square battery case 35 made of stainless steel that accommodates the electrode plate group 33 therein. The battery container 35 includes a battery can 37 having one end opened, and a battery lid 39. After the electrode plate group 33 is inserted into the battery can 37, the opening peripheral edge of the battery can 37 and the battery lid It is sealed by welding the peripheral part of 39.

  The electrode plate group 33 is configured by laminating a plurality of positive electrode plates 1 having ear portions 10B and negative electrode plates 32 having ear portions 36 with a separator 34 interposed therebetween.

  A positive electrode terminal 41 made of aluminum and a negative electrode terminal 43 made of copper are fixed to the battery lid 39. The positive electrode terminal 41 and the negative electrode terminal 43 have screw portions 41 a and 43 a that protrude to the outside of the battery container 35, respectively. An annular inner packing 45 is provided between the positive terminal 41 and the negative terminal 43 and the battery cover 39. An annular outer packing 47, a flat washer 49, and a toothed washer 51 are provided on the outer side of the battery lid 39 so as to face the inner packing 45 through the battery lid 39. Yes. The positive electrode terminal 41 and the negative electrode terminal 43 are fixed to the battery lid 39 by a nut 53 provided at the tip of the screw portion via an inner packing 45, an outer packing 47, a flat washer 49, and a toothed washer 51, respectively. . The portion of the battery lid 39 provided with the positive electrode terminal 41 and the negative electrode terminal 43 is sealed and sealed in the battery container 35 by the inner packing 45 and the outer packing 47. The positive electrode current collector ear portion 10B and the negative electrode current collector ear portion 36 are joined to the lower portions of the positive electrode terminal 41 and the negative electrode terminal 43 by ultrasonic welding, respectively, and the positive electrode plate 1 is connected to the positive electrode terminal 41 and the negative electrode plate 32. Is electrically connected to the negative terminal 43.

The battery lid 39 is provided with a gas discharge valve 39a welded with stainless steel foil and a liquid injection port (not shown). The gas discharge valve 39a has a function of cleaving the stainless steel foil and releasing the internal gas when the battery internal pressure increases. A non-aqueous electrolyte (not shown) in which lithium tetrafluoroborate (LiBF ₄ ) is dissolved in a mixed solvent of ethylene carbonate and dimethyl carbonate is injected from the injection port. After injection of the electrolyte, the liquid inlet is sealed with a liquid stopper.

  By using the positive electrode plate 1 having the shape of the present invention, it is possible to prevent an internal short circuit caused by burrs generated in the positive electrode plate 1.

[Second Embodiment]
FIG. 5 is a diagram showing a second embodiment of the electrode plate for a rectangular nonaqueous electrolyte storage cell of the present invention. In the second embodiment, in addition to the first corner portion 111 and the second corner portion 113, the third corner portion 115 is also provided with a third bending portion 155 that is a bending portion. The same members as those in the embodiment shown in FIG. 1 to FIG. 4 are given the same reference numerals as those in FIG. 1 to FIG.

  The third corner 115 has a second extension line 105 ′ (imaginary line extending along the second side) of the second side 105 and a fourth extension line 109 ′ (fourth side) of the fourth side. A third curved portion 155 that is convex toward the point where the imaginary line extending along the line intersects. The third bending portion 155 is formed by being cut by the cutting blade 125 so as to have the same shape as the first bending portion 121 and the second bending portion 123. By processing in this way, a short circuit inside the battery can be prevented more reliably.

[Third Embodiment]
FIG. 6 is a diagram showing a third embodiment of the electrode plate for a rectangular nonaqueous electrolyte storage cell of the present invention. In the third embodiment, the ear portion 210 </ b> B is provided in the vicinity of the center portion of the fourth side 209 away from the fourth corner portion 217. Therefore, the fourth corner portion 217 appears, and the fourth corner portion 217 is also formed with a fourth bending portion 257 that is a bending portion. The same members as those in the embodiment shown in FIG. 5 are given the same reference numerals as those shown in FIG.

  In the fourth corner 217, a third extension 207 ′ (imaginary line extending along the third side) of the third side 207 and a fourth extension 209 ″ (fourth side) of the fourth side The fourth curved portion 257 is formed to be convex toward the point where the imaginary line extending along the first curved portion 257. The fourth curved portion 257 includes the first curved portion 221 and the second curved portion. It is formed by cutting with a cutting blade 225 so as to have the same shape as 223. By processing in this way, it is possible to more reliably prevent a short circuit inside the battery regardless of the position where the ear portion is provided. .

[Fourth Embodiment]
FIG. 7 is a diagram showing a fourth embodiment of the electrode plate for a rectangular nonaqueous electrolyte storage cell of the present invention. The fourth embodiment is common to the second embodiment except that the fourth side 309 is inclined and the shape of the third curved portion 355 is different accordingly. The same members as those in the embodiment shown in FIG. 5 are denoted by the same reference numerals as those in FIG.

  The fourth side 309 is inclined so as to approach the first side 303 as the distance from the ear portion 310B increases. By doing in this way, it becomes possible for the electric current from each part of an electrode plate to reach an ear | edge part through the shortest conductive path, and can improve the discharge efficiency of an electric current. Further, as the fourth side 309 is inclined, the fourth extension line 309 ′ is also inclined, so that the third curved portion at the contact point 355 </ b> A between the fourth side 309 and the third curved portion 355. The third bending portion 355 is adjusted so that the acute angle formed by the tangent line 355 and the fourth extension line 309 ′ is 3 °. Therefore, in the present embodiment, only the cutting blade for cutting the third corner portion 315 has a different shape (a shape that matches the third curved portion 355).

[Fifth Embodiment]
FIG. 8 is a diagram showing a fifth embodiment of the electrode plate for a rectangular nonaqueous electrolyte storage cell according to the present invention. In the fifth embodiment, except that the fourth sides 409 located on both sides of the ear portion are inclined and the shapes of the third curved portion 455 and the fourth curved portion 457 are different accordingly. This is common with the third embodiment. The same members as those in the embodiment shown in FIG. 6 are given the same reference numerals as those shown in FIG.

  The fourth side 409 is located on both sides of the ear part 410B, and is inclined so as to approach the first side 403 as the distance from the ear part 410B increases. By doing in this way, it becomes possible for the electric current from each part of an electrode plate to reach an ear | edge part through the shortest conductive path, and can improve the discharge efficiency of an electric current. Further, as the fourth side 409 is inclined, the fourth extension lines 409 ′ and 409 ″ are also inclined, so that the third side at the contact point 455A between the fourth side 409 and the third curved portion 455 is also provided. The third curved portion 455 is adjusted so that the acute angle formed by the tangent line of the curved portion 455 and the fourth extended line 409 ′ is 3 °, similarly, the fourth side 409 and the fourth curved line The fourth bending portion 457 is adjusted so that the acute angle formed by the tangent line of the fourth bending portion 457 with the fourth extension line 409 ″ at the contact point 457A of the portion 457 is 3 °. Therefore, in this embodiment, the cutting blade for cutting the first and second corners, the cutting blade for cutting the third corner 415, and the fourth corner 417 are cut. Cutting blades with different shapes are used.

[Sixth Embodiment]
FIG. 9 is an example in which a corner is cut using a cutting blade having a shape different from that of the first embodiment, and FIG. 10 is a diagram illustrating an example of a cutting blade used at that time. The same members as those in the embodiment shown in FIG. 1 to FIG. 4 are given the same reference numerals as those in FIG. 1 to FIG.

FIG. 9 is a modified example of FIG. 2, and is an example in which the angles θ ₅₁₁ and θ ₅₁₂ are larger than 15 ° and smaller than 40 °. In FIG. 9, the first corner portion 511 is cut so that the angle θ ₅₁₁ = θ ₅₁₂ = 20 °. In this case, if an extended cutting blade as shown in FIG. 3 is used, there is a possibility that burrs may occur due to the cutting blade being displaced when the corner is cut. Therefore, as shown in FIG. 10, an arc-shaped cutting blade 525 can be used. If the central angle of the arc is larger than 90 °, there is a high possibility that the end of the cutting blade 525 will cut the portion other than the corner of the positive electrode plate 501. The central angle of the arc is smaller than 90 °. Therefore, the angle θ _o formed by the virtual line 561 and the virtual line 563 that intersect at the virtual center point 559 is smaller than 90 °. Even if the corners of the electrode plate are processed in this way, even if the cutting blade 525 and the side are displaced, a new corner is formed at the contact point while forming a curved portion at the corner of the electrode plate. This is practical.

  According to the first to fifth embodiments, the cutting blade 525 may be used to cut the second to fourth corners in addition to the first corner. is there.

  In the above embodiment, a lithium ion secondary battery is taken as an example. However, the present invention is not limited to this, and the electrode plate for a rectangular nonaqueous electrolyte storage cell of the present invention may be another type of secondary battery, lithium It can also be applied to capacitors such as ion capacitors.

  According to the present invention, the cutting blade also has a shape that coincides with each curved portion, and even if the cutting blade for machining the corner is slightly displaced from the predetermined position, the boundary between the curved portion and the side There is no possibility of generating small corners that become burrs. Therefore, according to the present invention, the curved portion can be easily formed at the corner of the electrode plate without requiring high processing accuracy, and the occurrence of a short circuit inside the container can be prevented. .

DESCRIPTION OF SYMBOLS 1 Positive electrode plate 2 Active material layer 3 1st edge | side 3 '1st extension line 5 2nd edge | side 5' 2nd extension line 7 3rd edge | side 7 '3rd extension line 9 4th edge | side 10 Positive electrode Current collecting plate 10A Current collecting plate body 10B Ear (positive electrode)
DESCRIPTION OF SYMBOLS 11 1st corner | angular part 13 2nd corner | angular part 15 3rd corner | angular part 17 4th corner | angular part 21 1st curved part 21A, 21B Contact 22A, 22B Tangent 23 2nd curved part 25 Cutting blade 27 Curved cutting Blade portions 27A, 27B End portions 29A, 29B Extended cutting blade portion 31 Lithium ion secondary battery 32 Negative electrode plate 33 Electrode plate group 34 Separator 35 Square battery container 36 Ear (negative electrode)
37 Battery can 39 Battery cover 41 Positive electrode terminal 43 Negative electrode terminal 45 Inner packing 47 Outer packing 49 Flat washer 51 Toothed washer 53 Nut

Claims (8)

A first side located on the bottom side of the battery case, a second side connected to one end of the first side via a first corner, the second side facing the second side, and the first side A third side connected to the other end of the side via the second corner, and a fourth side provided with an ear and facing the first side,
The first corner portion is constituted by a first curved portion that protrudes toward a point where a first extension line of the first side and a second extension line of the second side intersect. ,
The square non-aqueous water in which the second corner portion is constituted by a second curved portion that protrudes toward a point where the first extension line and the third extension line of the third side intersect. An electrode plate for an electrolyte storage cell,
The first bending portion has a tangent line of the first bending portion at a contact point between the first side and the first bending portion that is greater than 0 ° and less than 45 ° between the first extension line. An acute angle is formed, and the tangent line of the first curved portion at the contact point of the second side and the first curved portion is greater than 0 ° between the second extended line and 45. Formed to form an acute angle smaller than °,
The second bending portion has a tangent line of the second bending portion at a contact point between the first side and the second bending portion that is greater than 0 ° and less than 45 ° between the first extension line. An acute angle is formed, and a tangent line of the second curved portion at a contact point between the third side and the second curved portion is larger than 0 ° between the third extended line and 45. Formed to form an acute angle smaller than °,
One end of the fourth side and the second side are connected via a third corner, and the other end of the fourth side and the third side are connected via a fourth corner. Connected,
The third corner portion is constituted by a third curved portion that protrudes toward a point where the fourth extension line of the fourth side and the second extension line intersect;
The fourth corner portion is configured by a fourth curved portion that protrudes toward a point where the fourth extension line and the third extension line of the third side intersect;
The third bending portion has a tangent line of the third bending portion at a contact point between the fourth side and the third bending portion that is greater than 0 ° and less than 45 ° between the fourth extension line. An acute angle is formed, and a tangent line of the third curved portion at a contact point between the second side and the third curved portion is greater than 0 ° between the second extended line and 45. Formed to form an acute angle smaller than °,
The fourth curved portion has a tangent line of the fourth curved portion at a contact point between the fourth side and the fourth curved portion that is larger than 0 ° and smaller than 45 ° between the fourth extended line and the fourth curved portion. An acute angle is formed, and a tangent line of the fourth curved portion at a contact point between the third side and the fourth curved portion is larger than 0 ° between the third extended line and 45. Formed to form an acute angle smaller than °,
The square non-aqueous electrolyte storage cell, wherein the fourth side portions located on both sides of the ear portion are inclined so as to approach the first side as they move away from the ear portion. Electrode plate. A first side located on the bottom side of the battery case, a second side connected to one end of the first side via a first corner, the second side facing the second side, and the first side A third side connected to the other end of the side via the second corner, and a fourth side provided with an ear and facing the first side,
The first corner portion is constituted by a first curved portion that protrudes toward a point where a first extension line of the first side and a second extension line of the second side intersect. ,
The square non-aqueous water in which the second corner portion is constituted by a second curved portion that protrudes toward a point where the first extension line and the third extension line of the third side intersect. An electrode plate for an electrolyte storage cell,
The first bending portion has a tangent line of the first bending portion at a contact point between the first side and the first bending portion that is greater than 0 ° and less than 45 ° between the first extension line. An acute angle is formed, and the tangent line of the first curved portion at the contact point of the second side and the first curved portion is greater than 0 ° between the second extended line and 45. Formed to form an acute angle smaller than °,
The second bending portion has a tangent line of the second bending portion at a contact point between the first side and the second bending portion that is greater than 0 ° and less than 45 ° between the first extension line. An acute angle is formed, and a tangent line of the second curved portion at a contact point between the third side and the second curved portion is larger than 0 ° between the third extended line and 45. An electrode plate for a prismatic nonaqueous electrolyte storage cell, wherein the electrode plate is formed so as to form an acute angle smaller than °. One end of the fourth side and the second side are connected via a third corner, and the other end of the fourth side and the third side are connected via a fourth corner. Connected,
The third corner portion is constituted by a third curved portion that protrudes toward a point where the fourth extension line of the fourth side and the second extension line intersect;
The fourth corner portion is configured by a fourth curved portion that protrudes toward a point where the fourth extension line and the third extension line of the third side intersect;
The third bending portion has a tangent line of the third bending portion at a contact point between the fourth side and the third bending portion that is greater than 0 ° and less than 45 ° between the fourth extension line. An acute angle is formed, and a tangent line of the third curved portion at a contact point between the second side and the third curved portion is greater than 0 ° between the second extended line and 45. Formed to form an acute angle smaller than °,
The fourth curved portion has a tangent line of the fourth curved portion at a contact point between the fourth side and the fourth curved portion that is larger than 0 ° and smaller than 45 ° between the fourth extended line and the fourth curved portion. An acute angle is formed, and a tangent line of the fourth curved portion at a contact point between the third side and the fourth curved portion is larger than 0 ° between the third extended line and 45. The electrode plate for a prismatic nonaqueous electrolyte storage cell according to claim 2, wherein the electrode plate is formed so as to form an acute angle smaller than °.   4. The rectangular nonaqueous electrolyte electricity storage according to claim 3, wherein the portions of the fourth side located on both sides of the ear part are inclined so as to approach the first side as they are separated from the ear part. 5. Cell electrode plate. One end of the fourth side and the second side are connected by a third corner, and the ear is provided on the fourth side so that one side is continuous with the third side. And
The third corner portion is constituted by a third curved portion that protrudes toward a point where the fourth extension line of the fourth side and the second extension line intersect;
The third bending portion has a tangent line of the third bending portion at a contact point between the fourth side and the third bending portion that is greater than 0 ° and less than 45 ° between the fourth extension line. An acute angle is formed, and a tangent line of the third curved portion at a contact point between the second side and the third curved portion is greater than 0 ° between the second extended line and 45. The electrode plate for a prismatic nonaqueous electrolyte storage cell according to claim 2, wherein the electrode plate is formed so as to form an acute angle smaller than °.   6. The electrode plate for a rectangular nonaqueous electrolyte storage cell according to claim 5, wherein the fourth side is inclined so as to approach the first side as the distance from the ear portion increases.   The electrode plate for a prismatic nonaqueous electrolyte storage cell according to any one of claims 1 to 6, wherein the acute angle is an acute angle larger than 2 ° and smaller than 15 °.   The electrode plate for a prismatic nonaqueous electrolyte storage cell according to any one of claims 1 to 6, wherein the acute angle is an acute angle greater than 15 ° and smaller than 40 °.

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