JP6632264B2 - Method for producing small pieces of electrode plate and apparatus for cutting electrode plate - Google Patents

Description

  The present invention relates to a method and an apparatus for cutting an electrode plate, an electrode plate and a battery using the same.

  Patent Document 1 discloses a method of cutting a ceramic substrate so as to connect circular holes.

JP 2012-040708 A

  An electrode plate for a secondary battery can be cut by applying the method described in Patent Document 1. Such electrode plates are provided with holes arranged at predetermined intervals. In such a method, shavings of a whisker-like core material are generated around the hole near the cutting position. When a secondary battery is formed by laminating the cut electrode plates, such cutting dust causes a short circuit between the electrode plates. Therefore, a secondary battery using such an electrode plate has low reliability.

  An object of the present invention is to reduce the generation of cutting chips from an electrode plate and to increase the reliability of a secondary battery provided with such an electrode plate.

  One embodiment of the present invention is a method for manufacturing an electrode plate, in which a long electrode plate is continuously reduced into small pieces. In such a method, each time a long electrode plate provided with a core material having a mesh portion is repeatedly sent, the long electrode plate is repeatedly cut along a predetermined cut surface along with the mesh portion to perform such fragmentation.

  The mesh part has a mesh hole. The cut surface is substantially perpendicular to the longitudinal direction of the long electrode plate. For each cutting, the feed amount of the long electrode plate is adjusted in advance and cut. With this adjustment, the cut surface is separated from each of the two ends of the mesh hole by a specific margin or more. Such both ends are both ends in the longitudinal direction.

  One embodiment of the present invention is an electrode plate manufacturing apparatus which continuously cuts a long electrode plate into small pieces. Each time a long electrode plate having a core having a mesh portion having a mesh hole is repeatedly sent, the long electrode plate is cut repeatedly together with the mesh portion. The apparatus comprises a transport device for feeding the elongated electrode plate substantially parallel to a longitudinal direction of the elongated electrode plate. The apparatus includes a mold having a blade substantially orthogonal to a feeding direction of the long electrode plate.

  The transport device adjusts a feed amount of the long electrode plate. With this adjustment, the blade is separated from any one of the two ends of the mesh hole by a specific margin or more when viewed from above the long electrode plate. The both ends are both ends in the longitudinal direction. After the adjustment, the long electrode plate is cut with the mold.

  One embodiment of the present invention is an electrode plate including a core material having a mesh portion having mesh holes in rows. The electrode plate further includes two end faces that are substantially orthogonal to the row and that face each other with a mesh portion therebetween. The electrode plate satisfies at least one of the following conditions.

  Each of the end faces is apart from the mesh hole closest to the end face by a specific margin or more; a notch in contact with the end face and forming a row with the mesh holes is a direction parallel to the direction of the row. Has a specific margin depth at

  One embodiment of the present invention is a secondary battery including the electrode plate and not including the following electrode plate. Such an electrode plate includes a core material having a mesh portion having mesh holes in rows. The electrode plate further includes two end surfaces that are substantially orthogonal to the row and that face each other with the mesh portion interposed therebetween. Such an electrode plate does not satisfy any of the following conditions;

  Each of the end faces is apart from the mesh hole closest to the end face by a specific margin or more; a notch in contact with the end face and forming a row with the mesh holes is a direction parallel to the direction of the row. Has a specific margin depth at

  According to the present invention, the generation of cutting chips from the electrode plate can be reduced, and the reliability of a secondary battery including the electrode plate can be increased.

It is a top view of the long electrode board concerning an embodiment. It is a top view of the mesh part concerning an embodiment. 5 is a flowchart of a manufacturing method according to an example. It is a side view of the manufacturing device concerning an example. 1. It is an expanded sectional view in the VV cross section of the electrode plate shown in FIG. It is a top view of the manufacturing device concerning an example. It is a top view of the electrode plate concerning an example. It is an enlarged view of the electrode plate concerning an example. 5 is a flowchart of a manufacturing method according to a comparative example. It is a figure which shows the appearance distribution of the position of the cut surface which concerns on a comparative example and an Example. It is the top view 1 of the mesh part concerning a comparative example. It is the top view 1 of the mesh hole concerning a comparative example. It is the top view 2 of the mesh part concerning a comparative example. It is the top view 2 of the mesh hole concerning a comparative example.

[Repeated cutting and cut surface]
FIG. 1 shows a long electrode plate 30 used in the electrode plate manufacturing method according to the present embodiment. The long electrode plate 30 includes an active material 31 and a core material 32. The active material 31 forms a layer. The active material 31 is a positive electrode active material or a negative electrode active material. The core material 32 is a plate-shaped metal. The core 32 has a mesh portion 35. The mesh portion 35 is provided continuously without a break along the longitudinal direction of the long electrode plate 30.

  In the electrode plate manufacturing method shown in FIG. 1, the long electrode plate 30 is repeatedly fed along the longitudinal direction of the long electrode plate 30 as shown by the arrow. Each time the long electrode plate 30 is fed, the long electrode plate 30 is repeatedly cut together with the mesh portion 35.

  The long electrode plate 30 shown in FIG. 1 is cut at the cut surfaces 50a and 50b. The cut surfaces 50a and 50b indicate target positions for cutting. The long electrode plate 30 cut at the cut surface 50a is cut along the cut surface 50b after being sent along the arrow. Even after cutting at the cut surface 50b, the long electrode plate 30 is further fed and cut at the next cut surface. Based on the repetition of the cutting, the long electrode plate 30 is continuously divided into small pieces.

  The mesh part 35 shown in FIG. 1 includes mesh holes 55a-c and other mesh holes. These mesh holes are through holes. Mesh holes represented by mesh holes 55a form rows 51a-d and other rows. The columns represented by the column 51a are parallel to each other. The row represented by the row 51a is parallel to the longitudinal direction of the long electrode plate 30. The cut surfaces 50a and 50b are substantially orthogonal to the row represented by the row 51a.

  The mesh holes typified by the mesh holes 55a shown in FIG. 1 are arranged in a staggered manner in rows 51a, c corresponding to odd rows and rows 51b, d corresponding to even rows. In such a staggered arrangement, the distinction between odd rows and even rows is for convenience. It is possible to read odd columns as even columns and even columns as odd columns. When the long electrode plate 30 is viewed from the side, the mesh holes of the odd rows and the even rows overlap each other. It is preferable that the displacement of the positions of the mesh holes between the odd-numbered rows and the even-numbered rows is equal to half the interval between the mesh holes.

  The feed amount of the long electrode plate 30 is adjusted in advance each time the sheet is cut along the cut surfaces 50a and 50b and other cut surfaces shown in FIG. FIG. 2 is an enlarged view of the mesh portion 35 shown in FIG. 1 in a range II. By adjusting the feed amount, the cut surfaces 50a and 50b and other cut surfaces shown in FIG. 1 are positioned within the cut range 52a, b, or 53 (see FIG. 2).

[Range 1 of cut surface]
Row 51b shown in FIG. 2 has mesh holes 55a. The mesh hole 55a may be a square hole or a round hole. The same applies to other mesh holes. The mesh holes 55a in the figure are square holes. The mesh hole 55a has a rectangular parallelepiped shape.

  In a direction parallel to the direction of the row 51b shown in FIG. 2, the mesh hole 55a has both ends and ends 56a and 56b. The ends 56a and 56b oppose each other across the center of the mesh hole. The end 56b is located downstream of the end 56a in the feeding direction of the long electrode plate 30 shown in FIG. The ends 56a and 56b are formed by the side surfaces of the rectangular parallelepiped. The same applies to other mesh holes other than the mesh hole 55a. The same applies to vertical columns other than the column 51b.

  The cutting areas 52a and 52b shown in FIG. 2 are separated from both of the ends 56a and 56b. The cutting range 52a is separated from the end 56a by the margin 58a. The cutting area 52a is further away from the end 56b. The cutting range 52b is separated from the end 56b by the margin 58d. The cutting range 52b is further away from the end 56a.

  The cut surface passing through the cut ranges 52a, b shown in FIG. 2 is separated from any of the ends 56a, b by a margin 58a or more or a margin 58d or more.

  The row 51c shown in FIG. 2 has mesh holes 55b and 55c. Row 51c is located next to row 51b. The mesh holes 55b are located upstream of the mesh holes 55a and 55c in the feeding direction of the long electrode plate 30 shown in FIG. The mesh hole 55c is located downstream of the mesh holes 55a and 55b in the feed direction.

  In a direction parallel to the direction of the row 51c shown in FIG. 2, the mesh hole 55b has both ends and ends 57a and 57b. The end portion 57b is located downstream of the end portion 57a in the feeding direction of the long electrode plate 30 shown in FIG. Similarly, the mesh hole 55c has both ends and ends 57c and 57d. The end 57d is located downstream of the end 57c in the feed direction.

  The cutting areas 52a, 52b shown in FIG. 2 are spaced from any of the ends 57a-d. The cutting range 52a is separated from the end 57b by the margin 58b. The cutting area 52a is further separated from the end 57a. The cutting range 52b is separated from the end 57c by the margin 58c. The cutting range 52b is further separated from the end 57d.

  A cutting plane passing through the cutting ranges 52a and 52b shown in FIG. 2 is separated from any end 57a-d by a margin 58b or more or a margin 58c or more.

  A cutting plane passing through the cutting ranges 52a and 52b shown in FIG. 2 continuously passes through mesh holes of rows 51a and 51c corresponding to odd rows and rows 51b and 51d corresponding to even rows. In addition, the cut surface has a specific margin from any one of the ends of the mesh holes in the rows 51a and c and the rows 51b and d, including the ends 56a and b and the ends 57a-d. It is separated above. The positioning of the cut surface is performed by adjusting the feed amount of the long electrode plate 30 in FIG. 1 in advance.

  The specific margin is the smallest margin among the margins 58a-d shown in FIG. However, the figure is a schematic one and does not represent the actual size of the margin. Such a specific margin is greater than 0 μm. Such a specific margin can be 1 mm or less. Such a specific margin, when cutting the core material, the width of the blade, the original width of the blade, so that the blade for cutting does not cut the end of the mesh hole to generate cutting chips of a certain size or more. What is necessary is just to determine in consideration of the inclination error etc. from the cutting direction (direction orthogonal to the feed direction of the long electrode plate 30). Such specific margins include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, Examples are 500, 600, 700, 800 and 900 μm.

[Range 2 through the cut surface]
The cutting range 53 shown in FIG. 2 is located between the mesh holes 55b and 55c and on the mesh hole 55a. The cutting range 53 shown in FIG. 2 is separated from any of the ends 57b and 57c. The cutting range 53 is separated from the end 57b by the margin 59a. The cutting range 53 is separated from the end 57c by the margin 59b.

  As shown in FIG. 1, when the long electrode plate 30 is viewed from the side, the mesh holes of the rows 51 a and c corresponding to the odd rows and the rows 51 b and d corresponding to the even rows overlap each other. Therefore, the cutting range 53 is further separated from the ends 56a and 56b than the ends 57b and 57c.

  The cutting plane passing through the cutting range 53 shown in FIG. 2 is separated from any end including the ends 56a, b and the ends 57a-d by a margin 59a or more or a margin 59b or more.

  The cut surface passing through the cutting range 53 shown in FIG. 2 passes through the mesh holes in one of the odd rows represented by the rows 51a and 51c and the even rows represented by the rows 51b and 51d. It does not pass through the mesh holes of the other of the odd and even rows. In the figure, it passes through the mesh hole 55a. The cut surface is separated from any one of the ends 56a, b of the mesh holes 55a by a specific margin or more.

  The cut plane passing through the cutting range 53 shown in FIG. 2 passes between two mesh holes 55b and 55c of the even rows corresponding to the other of the odd rows 51a and 51c and the even rows 51b and d. The mesh holes 55b and 55c are adjacent to each other. The cut surface is separated from any one of the two mesh holes 55b and 55c by a specific margin or more. The positioning of the cut surface is performed by adjusting the feed amount of the long electrode plate 30 in FIG. 1 in advance.

  The specific margin is the smallest margin among the margins 59a and 59b shown in FIG. However, the figure is a schematic one and does not represent the actual size of the margin. Such a specific margin is greater than 0 μm. Such a specific margin can be 1 mm or less. Such a specific margin, when cutting the core material, the width of the blade, the original width of the blade, so that the blade for cutting does not cut the end of the mesh hole to generate cutting chips of a certain size or more. What is necessary is just to determine in consideration of the inclination error etc. from the cutting direction (direction orthogonal to the feed direction of the long electrode plate 30). Such specific margins include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, Examples are 500, 600, 700, 800 and 900 μm.

[Effects and Modifications of Embodiment]
Positioning of the cut surface based on the cut areas 52a, 52b, and 53 shown in FIG. 2 is performed by adjusting the feed amount of the long electrode plate 30 in FIG. Thereby, generation of cutting waste can be reduced. Such effects will be described in detail in Examples and Comparative Examples described later.

  In the interpretation of the cutting ranges 52a, 52b, and 53 shown in FIG. 2, it is possible to read the odd-numbered column as an even-numbered column and the even-numbered column as an odd-numbered column. In which of the cutting areas 52a, b and 53 the cutting plane represented by the cutting planes 50a and 50b shown in FIG. 1 is arranged can be arbitrarily determined for each cutting plane. That is, the cut surface may be arranged exclusively in any one of the cut ranges 52a, 52b, and 53. Further, any suitable one of the cutting ranges 52a, 52b and 53 may be selected for each cutting surface.

  The feed amount can be similarly adjusted by using a mesh portion in which mesh holes are arranged in a lattice in the longitudinal direction and the lateral direction of the long electrode plate 30 instead of the mesh portion 35 shown in FIG. Also, when the long electrode plate 30 is viewed from the side, the feed amount can be similarly adjusted by using mesh portions in which the mesh holes of the odd rows and the even rows do not overlap each other.

[Production flow and production equipment]
An embodiment will be described with reference to FIGS. FIG. 3 shows an electrode plate manufacturing method including steps 21 to 28. 4 and 6 show an electrode plate manufacturing apparatus for performing the electrode plate manufacturing method.

  Such a manufacturing apparatus repeatedly cuts the long electrode plate 30 each time the long electrode plate 30 having the core material 32 is fed as shown in FIG. Such a manufacturing apparatus continuously cuts the long electrode plate 30 into small pieces. As shown in FIG. 1, since the core material 32 has the mesh portion 35, the manufacturing apparatus cuts the long electrode plate 30 together with the mesh portion 35.

  FIG. 4 shows a part in the manufacturing apparatus, in which steps until the long electrode plate 30 is formed are executed. By the steps 21 to 25, the long electrode plate 30 is continuously formed.

  Step 21 shown in FIG. 3 is a step of winding a thin metal plate to form the roll 20 shown in FIG. Step 22 shown in FIGS. 3 and 4 is a step of extracting the thin plate 18 from the roll 20 and forming a square hole in the thin plate 18. The square hole may be formed by punching using a mold.

  The square holes are mesh holes represented by the mesh holes 55a shown in FIGS. As shown in FIGS. 1 and 2, the square holes gather to form a mesh portion 35. Thereby, the thin plate 18 shown in FIG. 4 is made into the core material 32 having the mesh portion 35 as shown in FIGS. As shown in FIG. 4, when the roll 20 is set to the upstream side, the core material 32 is sequentially sent toward the downstream side.

  Step 23 shown in FIGS. 3 and 4 is a step of forming a marking on the core material 32. The marking is performed before the rolling in step 25 described later. Details of the marking mode will be described later. Step 24 is a step of applying the active material 31 to the core material 32. Through this step, a layer of the active material 31 is formed on the surface of the core material 32.

  As shown in FIG. 1, the layer has a band shape parallel to the direction in which the core material 32 is fed. The active material 31 is applied to the core 32 so as to cover the mesh portion 35. The active material 31 also enters a square hole provided in the core material 32.

  Step 25 shown in FIGS. 3 and 4 is a step of rolling the core material 32 and the layer of the active material 31 together to form a long electrode plate 30. Thus, the long electrode plate 30 including the core material 32 and the active material 31 is formed.

  FIG. 5 shows a VV cross section of the long electrode plate 30 shown in FIG. As shown in FIG. 5, in step 25, the core material 32 is stretched. Therefore, the interval between the mesh holes is widened. Also, the mesh holes themselves become large.

  As shown in FIG. 5, the mesh holes 55d and 55e downstream of the portion where the rolling is performed in step 25 are larger than the mesh holes 55f and 55g upstream thereof. The mesh holes 55d and 55e are equivalent to the mesh holes ac described above. The core material 32 sandwiched between them also extends parallel to the direction in which the long electrode plate 30 is fed.

  As shown in FIG. 4, the long electrode plate 30 is formed while the thin plate 18 is continuously pulled out from the roll 20. For this reason, the long electrode plate 30 includes a downstream portion on which the active material 31 is already applied and an upstream portion on which the active material 31 is applied.

  The manufacturing apparatus shown in FIGS. 4 and 6 includes a not-shown transfer device. The conveying device feeds the long electrode plate 30 so as to pull out the thin plate 18 from the roll 20. In addition, the transport device sends the long electrode plate 30 in a direction along a row of square holes represented by the row 51a shown in FIG.

  As shown in FIG. 6, the long electrode plate 30 is provided with nine bands of the active material 31. Such a band is provided in step 24 shown in FIGS. In step 23 shown in FIG. 3, marking rows 33a and 33b are provided on the long electrode plate 30 as shown in FIG. The markings constituting the marking rows 33a and 33b shown in FIG.

  In step 25 shown in FIG. 5, the distance between the mesh holes typified by the mesh holes 55d and 55e increases. Also, the mesh holes themselves become large. In step 25 shown in FIGS. 3 and 4, the markings extend following the mesh holes. In addition, it becomes larger following the mesh holes. Therefore, the positional relationship between the marking and the mesh holes is maintained.

  As shown in FIG. 6, the marking rows 33a and 33b are parallel to the row of square holes represented by the row 51a. In the figure, the row 51a is drawn as a representative of the row of square holes. When the long electrode plate 30 is viewed in a plan view, it is preferable that the marking rows 33a and 33b are parallel to a row of square holes represented by the row 51a. Similarly, the marking rows 33a and 33b are preferably parallel to the band of the active material 31.

  As shown in FIG. 6, each of the markings constituting the marking row 33a is arranged so as to have a corresponding relationship with the position of the square hole of the row 51a. The markings constituting the marking rows 33a and 33b are provided at the same intervals as these square holes. These markings are provided on both sides in the short direction of the long electrode plate 30 so as to sandwich the mesh portion having the row 51a and the active material 31 on the mesh portion.

  The respective markings constituting the marking rows 33a and 33b shown in FIG. 6 can be formed in step 23 as follows. For example, each marking may be a square hole equivalent to the mesh hole 55a shown in FIGS. Each of such markings may be formed by punching using a mold as in the case of the mesh holes.

  Each marking may be formed by irradiating the surface of the core material 32 shown in FIG. 4 with a laser to modify the core material 32. In such formation, the position of the mesh hole may be read before the active material 31 is applied. The laser may be applied to a position synchronized with the read position of the mesh hole. The denatured part functions as the marking.

  Instead of irradiating the laser as described above, ink may be applied onto the core material 32 shown in FIG. The ink may be applied to a position synchronized with the read position of the mesh hole. The portion where the ink is applied functions as the marking.

  Step 26 shown in FIG. 3 is a step of reading each of the markings constituting the marking rows 33a and 33b at the detection positions 37a and 37b shown in FIG. The square hole having the above-mentioned correspondence with the marking passes through the same position as the detection positions 37a and 37b in the direction parallel to the direction in which the long electrode plate 30 is fed at the same time as the marking. The direction in which the long electrode plate 30 is fed is parallel to the longitudinal direction of the long electrode plate. The direction in which the long electrode plate 30 is fed is represented by an arrow shown in FIG.

  In other words, the marking and the square hole pass synchronously between the detection positions 37a and 37b shown in FIG. The fact that the marking has such a positional relationship with respect to the square hole is referred to herein as “the synchronization” of the marking with respect to the square hole. As described above, the positional relationship between the marking and the mesh hole is maintained before and after step 25. Therefore, such synchronization is maintained before and after step 25.

  The markings constituting the marking rows 33a and 33b shown in FIG. 6 are synchronized with the row of square holes represented by the row 51a. By reading the marking at the detection positions 37a and 37b, the position of the square hole can be estimated. Reading is performed before cutting. The manufacturing apparatus includes detectors 41a and 41b. The detectors 41a and 41b read the markings at the detection positions 37a and 37b, respectively.

  Step 27 shown in FIG. 3 is a step of adjusting the feed amount of the long electrode plate 30 shown in FIG. In step 27, a target position at which cutting is performed in a direction parallel to the direction in which the long electrode plate 30 is fed is determined based on the above estimation. Therefore, the feed amount can be adjusted based on the marking. Cut surfaces 50a and 50b are shown as target positions. At 50a, the cutting has already been completed.

  The manufacturing apparatus shown in FIG. The mold 40 has a blade (not shown). The blade is substantially perpendicular to the feeding direction of the long electrode plate 30.

  The above-described transport device adjusts the feed amount of the long electrode plate 30 so that the blade overlaps the cut surface 50b when the long electrode plate 30 shown in FIG. 6 is viewed in plan. Accordingly, when the long electrode plate 30 is viewed in a plan view, the above-described blade can be identified from any of the two ends of the square hole in a direction parallel to the square hole row represented by the row 51a. More than the margin.

  The markings of the marking rows 33a and 33b shown in FIG. 6 are provided on both sides of the long electrode plate 30, respectively. The feed amount may be adjusted independently on both sides of the long electrode plate 30 based on the marking. In other words, the feed amount may be adjusted separately for the left and right sides. With this adjustment, the deviation between the direction of the cut surface 50b and the direction of the mold 40 can be adjusted. That is, the deviation between the direction of the cutting surface 50b and the direction of the blade can be adjusted.

  Step 28 shown in FIG. 3 is a step of cutting the long electrode plate 30 with the mold 40 shown in FIG. Cutting is performed on the cut surface determined as described above. After the adjustment, the manufacturing apparatus cuts the long electrode plate 30 with the mold 40. Also cut between the strips of each active material. The manufacturing apparatus forms a small electrode plate typified by the small electrode plates 44a and 44b. In the drawing, the small piece electrode plate 44b is to be formed.

  After performing step 28 shown in FIG. 3, the process returns to step 26. Thereafter, steps 26-28 are repeated. Each time the long electrode plate 30 shown in FIG. 6 is repeatedly sent, the long electrode plate 30 is repeatedly cut. The feed amount of the long electrode plate 30 is adjusted in advance in step 27 for each cutting.

[Positioning holes, etc.]
In step 27 shown in FIG. 3, positioning holes typified by positioning holes 48a and 48b are provided on the core material 32 of the long electrode plate 30 before fragmentation, as shown in FIG. In the small electrode plates typified by the small electrode plates 44a and 44b, exposed portions typified by the exposed portions 46a and 46b of the core material 32 are provided. These exposed portions are provided with positioning holes typified by positioning holes 48a and 48b. When a plurality of small electrode plates 32 are stacked, the edges of the small electrode plates can be precisely aligned by inserting pins into the positioning holes of each small electrode plate 32.

  The positioning hole 48a shown in FIG. 6 is preferably formed at the same time as the cutting at the cut surface 50a. The cut surface located downstream of the positioning hole 48a with respect to the direction in which the long electrode plate 30 is fed is the cut surface 50a. The positioning hole 48 is separated from the active material 31.

  FIG. 7 is a plan view of the most downstream portion of the long electrode plate 30 in a plan view. The positioning hole represented by the positioning hole 48a is one of the positioning holes provided in the exposed portion represented by the exposed portion 46a.

  The distance between the positioning hole 48a and the cut surface 50a shown in FIG. 7 is set shorter than the feed amount when the long electrode plate 30 is sent for cutting at the next cut surface 50b. The positioning hole 48a is the most downstream one of the positioning holes of the exposed portion 46a in the direction in which the long electrode plate 30 is fed. Other positioning holes typified by the positioning hole 48b are the same as the positioning holes 48a.

  With respect to the positioning hole located most downstream in the direction in which the long electrode plate 30 is fed as shown in FIG. 7, the distance between the cutting surface located downstream in the same direction and closest to the positioning hole and the positioning hole Is constant for each cut at each cut surface. That is, the distance between the positioning hole 48b and the cut surface 50b is equal to the distance between the positioning hole 48a and the cut surface 50a. The same applies to the relationship with other positioning holes and cut surfaces. This can be realized by simultaneously cutting the long electrode plate and forming the positioning holes using the same mold or the like.

  In step 27 shown in FIG. 3, notches 45 are formed upstream and downstream of the small piece electrode plates 44a and 44b as shown in FIG. These notches 45 sandwich the above-described positioning holes. Further, the extra piece 47 is cut off from the long electrode plate 30. It is preferable that the extra pieces 47 include the marking row 33a. It is preferable that the part of the core material 32 including the marking row 33b is also cut off in the same manner.

[Small electrode plate]
FIG. 8 is an enlarged view of a small piece electrode plate 44a. The small piece electrode plate 44 a includes the core material 32. The core 32 has a mesh portion 35. The mesh portion 35 has a mesh hole represented by the mesh hole 55a. These mesh holes form a row represented by rows 51a-d.

  The small piece electrode plate 44a shown in FIG. 8 has two end faces. End face 78 is one of the two end faces. The other end face is not shown. The two end faces are substantially orthogonal to the row. The two end faces face each other with the mesh portion 35 interposed therebetween.

  The notch 75 shown in FIG. 8 is in contact with the end face 78 and forms a row with the mesh holes 55a. The innermost part 76 is the innermost part of the notch 75. The innermost part 76 is the innermost part in a direction parallel to the direction of the row. The end face 78 satisfies one of the following conditions. The same applies to the end face facing the end face 78.

(I) The end face 78 is separated from the mesh hole 55b closest to the end face 78 by a length equal to or more than a specific margin 77.

(Ii) Each of the notches 75 has a depth equal to or greater than the length of the specific margin 79 in a direction parallel to the direction of the column represented by the columns 51a to 51d. In other words, the end face 78 is separated from the innermost part 76 by a length equal to or more than the specific margin 79.

  Such a specific margin is greater than 0 μm. Such a specific margin can be 1 mm or less. Such a specific margin, when cutting the core material, the width of the blade, the original width of the blade, so that the blade for cutting does not cut the end of the mesh hole to generate cutting chips of a certain size or more. What is necessary is just to determine in consideration of the inclination error etc. from the cutting direction (direction orthogonal to the feed direction of the long electrode plate 30). Such specific margins include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, Examples are 500, 600, 700, 800 and 900 μm.

[Secondary battery]
The secondary battery according to this embodiment includes the small piece electrode plate 44a shown in FIG. Such a secondary battery does not include the following electrode plates. Such an electrode plate is an electrode plate provided with a core material having a mesh portion having mesh holes arranged in a row similarly to the small piece electrode plate 44a.

  The electrode plate further includes two end surfaces substantially perpendicular to the rows of the mesh holes and facing each other with the mesh portion interposed therebetween, similarly to the small electrode plate 44a shown in FIG. However, unlike the small piece electrode plate 44a, such an electrode plate does not satisfy any of the above-described conditions (i) and (ii).

The secondary battery includes a plurality of electrode plates equivalent to the small electrode plate 44a shown in FIG. It is preferable that these electrode plates are overlapped. The distance between the end face 78 and the nearest positioning hole 48a is constant in each electrode plate. Therefore, when the respective electrode plates are positioned by inserting pins or the like into the positioning holes, the end faces 78 are aligned. Then, the plurality of superposed electrode groups are inserted into the battery case from the end face 78. If the end surfaces 78 are not aligned, a part of the electrode plate may come into contact with the bottom surface of the battery case. However, by aligning the end surfaces, the contact can be prevented. In the present invention, the length of each electrode plate may not be the same by adjusting the feed amount. However, even in such a case, a secondary battery can be suitably manufactured.
Note that the end face opposite to the end face 78 is downstream in the insertion direction and has a space between the end face 78 and the battery case.

  The generation of cutting chips is reduced in the electrode plate. The generation of cutting chips is reduced in each of the electrode plates constituting the secondary battery. For this reason, the reliability of the secondary battery can be improved.

[Alternative to marking]
Instead of the marking rows 33a and 33b shown in FIG. 6, a signature on the long electrode plate 30 that is different from the marking can be used for estimating the position of the mesh hole. In the present specification, such a signature and a marking are collectively called a signature.

  The signature on the long electrode plate 30 is a pattern formed by repeating the shading of the active material 31 after rolling shown in FIG. Such a sign is generated on a row of mesh holes represented by the mesh holes 55d and 55e. The layer of the active material 31 after the rolling is substantially flat.

  The rolled portion 39a shown in FIG. 5 is located in or on the mesh holes represented by the mesh holes 55d and 55e. The rolled portion 39b is located on the core material 32 between these mesh holes.

  Unlike the rolled portion 39a, the rolled portion 39b is compressed together with the core material 32. Therefore, in the rolling in step 25, the crush amount of the rolled portion 39b is larger than the crush amount of the rolled portion 39a. Therefore, the active material 31 in the rolled portion 39b becomes denser than the active material 31 in the rolled portion 39a.

  Due to the difference in the density of the active material 31 shown in FIG. 5, the color of the active material 31 is darker on the surface of the rolled portion 39b than on the surface of the rolled portion 39a. Shading occurs between the surface of the rolled portion 39b and the surface of the rolled portion 39a.

  On the row of mesh holes typified by the mesh holes 55d and 55e shown in FIG. 5, a pattern consisting of the repetition of such shading appears in parallel with the row. It is clear from the origin that such a pattern is synchronized with the mesh holes.

  Such repetition of shading can be detected by a detector similarly to the above-mentioned marking. Preferably, the detector is a camera. The marking in the above-described method can be replaced by the shading. In step 26 shown in FIG. 3, a pattern consisting of repetition of shading is read.

[Comparative example]
A comparative example will be described with reference to FIGS. The problems to be solved by the embodiments will be described in detail. FIG. 9 shows a manufacturing method according to a comparative example. The method of the comparative example is different in that steps 23, 26, and 27 shown in FIG. 3 are not provided. That is, the feed amount of the long electrode plate 30 is not adjusted based on the marking rows 33a and 33b as shown in FIG.

  On the other hand, step 19 is provided between step 25 and step 28 as shown in FIG. The fixed-size feeding process shown in step 19 is to make the feeding amount of the long electrode plate 30 shown in FIG. 6 constant at a predetermined value. In the comparative example, after performing step 28, the process returns to step 19. Thereafter, steps 19 and 28 are repeated.

  In the comparative example, the long electrode plate 30 shown in FIG. 6 is repeatedly cut every time the long electrode plate 30 shown in FIG. However, the feed amount of the long electrode plate 30 at each cut is constant. Accordingly, the length of the small electrode plates typified by the small electrode plates 44a and 44b is constant.

  FIG. 10 shows the appearance distribution of the positions of the cut surfaces according to the comparative example and the example. The appearance distribution 71 represents the appearance distribution of the cut surface in the comparative example. The horizontal axis of the appearance distribution 71 is the appearance frequency of the cut surface. The vertical axis indicates coordinates in a direction parallel to the row of mesh holes.

  The appearance distribution 72 represents the appearance distribution of the cut surface in the embodiment. Of the cutting ranges described with reference to FIG. 2 for the embodiment, a cutting range 52b is illustrated as a representative. The vertical and horizontal axes of the appearance distribution 72 are the same as those of the appearance distribution 71.

  In the embodiment shown in the appearance distribution 72 of FIG. 10, the feed amount of the long electrode plate 30 shown in FIG. 6 is adjusted so that the cut surface is entirely within the cut range 52b. In the comparative example, in the direction parallel to the rows of the mesh holes, the cut surfaces appear at almost random positions.

  One of the reasons that the cut surface appears at a random position in the appearance distribution 71 of FIG. 10 is that the length of the long electrode plate 30 shown in FIGS. Accumulation of shifts may cause shifts. Another reason is that the size and the interval of the mesh holes after rolling represented by the mesh holes 55c shown in FIG.

  FIG. 11 is a plan view of the mesh portion 35 according to the comparative example. The cut surface 60 according to the comparative example is close to the end 57c. The distance between the cut surface 60 and the end 57c is smaller than the margin 59b shown in FIG.

  FIG. 12 is a plan view of the mesh hole 55c according to the comparative example. The end surface 61 is generated by cutting the mesh portion 35 at the cutting surface 60 in FIG. The core material 32 is easily broken between the end faces 61 and 57b. As a result of the breaking, cutting chips 64 are generated. When the secondary batteries are formed by laminating the electrode plates, the cutting chips 64 behave as foreign matters that can cause a short circuit between the electrode plates.

  FIG. 13 is a plan view of the mesh portion 35 according to the comparative example. The cut surface 65 according to the comparative example intersects the end 57c. On the other hand, in the embodiment, the feed amount of the long electrode plate is adjusted separately for the left and right as described above, so that the cut surface passing through the cut range 52b shown in FIG. 10 is substantially parallel to the end 57c.

  FIG. 14 is a plan view of the mesh hole 55c according to the comparative example. The end surface 66 is generated by cutting the mesh portion 35 at the cutting surface 65 in FIG. The core material 32 is broken between the end faces 66 and 57b. As a result of the fracture, a whisker-like or burr-like projection 67 is generated. When the secondary batteries are formed by laminating the electrode plates, the protrusion 67 may cause a short circuit between the electrode plates.

  In the embodiment, the feed amount of the long electrode plate 30 shown in FIG. 6 is adjusted each time cutting is performed so that the above-described specific margin can be provided. Therefore, the cutting chips 64 shown in FIG. 12 and the projections 67 shown in FIG. Therefore, when a secondary battery is formed by laminating the electrode plates, a short circuit between the electrode plates can be prevented.

  The present invention is not limited to the above, and can be appropriately changed without departing from the gist of the present invention.

18 thin plate, 19 steps, 20 rolls, 21-28 steps, 30 long electrode plate, 31 active material, 32 core material, 33a, b marking row, 35 mesh part, 37a, b detection position, 39a, b rolled part , 40 mold, 41a, b detector, 44a, b small piece electrode plate, 45 notch, 46a, b exposed part, 47 extra piece, 48a, b positioning hole, 50a, b cut surface, 51a-d row, 52a, b cutting range, 53 cutting range, 55a-g mesh hole, 56a, b end, 57a-d end, 58a-d margin, 59a, b margin, 60 cutting surface, 61 end surface, 64 cutting waste, 65 Cut surface, 66 end face, 67 protrusion, 71, 72 Appearance distribution, 76 innermost part, 77 margin, 78 end face, 79 margin

Claims (6)

Each time a long electrode plate provided with a core material having a mesh portion is repeatedly sent, the long electrode plate is repeatedly cut along with the mesh portion at a predetermined cut surface, whereby the long electrode plate is continuously fragmented. An electrode plate manufacturing method,
The mesh portion has a mesh hole,
The cut surface is substantially orthogonal to the longitudinal direction of the long electrode plate,
For each of the cuts, the feed amount of the long electrode plate is adjusted in advance and cut,
The adjustment is performed so that the cut surface is separated from any end of the mesh hole in the longitudinal direction by a specific margin or more from any end,
The mesh holes are arranged in an odd-numbered row and an even-numbered row parallel to the longitudinal direction, and are staggered,
The cut surface continuously passes through the mesh holes of the odd-numbered rows and the even-numbered rows, and any one of the two ends of the odd-numbered rows and the even-numbered rows of the mesh holes passing through the cut face. The feed amount of the long electrode plate is adjusted in advance so as to be separated from the part by a specific margin or more,
Electrode plate manufacturing method. Simultaneously with the cutting, a positioning hole is provided on the core material of the long electrode plate before fragmentation, which is separated from an active material,
The distance between the positioning hole and the cut surface is shorter than the feed amount when the long electrode plate is sent for the next cut, and is constant for each cut.
The method for manufacturing an electrode plate according to claim 1. The mesh holes form a row parallel to the longitudinal direction,
By rolling the core material to the long electrode plate,
Before performing the cutting, a sign on the long electrode plate is detected in parallel with the row and synchronized with the mesh hole,
Adjusting the feed amount based on the sign;
The method for producing an electrode plate according to claim 1. The signature is
Marking provided on the core material before the rolling, and / or repetition of shading of the active material on the row of the mesh holes,
The method for manufacturing an electrode plate according to claim 3. The sign is the marking,
The marking is provided on both sides in the short direction of the long electrode plate, so as to sandwich the mesh portion,
Before performing the cutting, read the markings on both sides,
Adjusting the feed amount independently on each side based on the markings on both sides,
The method for manufacturing an electrode plate according to claim 4. Each time a long electrode plate having a core material having a mesh portion having a mesh hole is repeatedly sent, the long electrode plate is cut into pieces by repeatedly cutting the long electrode plate, whereby the long electrode plate is continuously fragmented. , An electrode plate manufacturing apparatus,
A transport device that sends the long electrode plate substantially parallel to a longitudinal direction of the long electrode plate,
A mold having a blade substantially orthogonal to a feeding direction of the long electrode plate,
With
Where the mesh holes are arranged in an odd-numbered row and an even-numbered row, both of which are parallel to the longitudinal direction and are arranged in a staggered manner, the transport device, when viewed in plan with respect to the long electrode plate, the blade is While continuously passing through the mesh holes of the odd-numbered rows and the even-numbered rows, from both ends in the longitudinal direction of the mesh holes of the odd-numbered rows and the even-numbered rows passed by the blade, from any end of the mesh holes. Adjust the feed amount of the long electrode plate so as to be separated by a specific margin or more,
After the adjustment, cut the long electrode plate with the mold.
Electrode plate manufacturing equipment.

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