JP2012174579A - Wound type battery, and manufacturing method and manufacturing apparatus of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wound type battery capable of preventing trouble such as crack, fracture and breakage from occurring even in a case of flat-pressing after an electrode plate is wound, a manufacturing method and a manufacturing apparatus of the battery.SOLUTION: The wound type battery comprises an electrode plate which is one or both of a positive electrode plate 10 and a negative electrode plate 20 and includes one or both of an electrode active material layer having a groove portion 13a formed in a groove shape in a short-side direction on an inner peripheral surface side at a bent part B of a flat body 200 formed by flat-pressing, and an electrode active material layer having a notch 11a or a groove portion formed in a short-side direction on an outer peripheral surface side at the bent part B of the flat body 200 formed by flat-pressing. With this configuration, the groove portion 13a and the like are formed on one or both of the inner peripheral surface side and the outer peripheral surface side to prevent the trouble such as the crack, fracture and breakage of the electrode plate (especially, electrode active material layer) from occurring compared with a conventional art.

Description

  The present invention relates to a wound battery including at least a positive electrode plate, a negative electrode plate, and a separator, a manufacturing method for manufacturing the wound battery, and a manufacturing apparatus for the wound battery.

  Conventionally, an electrode wound in a spiral shape has a depth of 1/10 to 1/3 of the thickness of the electrode at equal intervals of 0.5 to 2.0 mm along the longitudinal direction on both front and back surfaces. An example of a technique related to a battery electrode in which a plurality of streak grooves are provided, and the streak grooves on the electrode surface side and the streak grooves on the back surface side are different from each other is disclosed (for example, see Patent Document 1). This battery electrode is composed of a band-shaped metal porous body having a three-dimensionally continuous space and an active material filled in the space. As shown in FIG. 3 of Patent Document 1, when the electrode is wound in a spiral shape, a plurality of streak grooves act to prevent problems such as cracking, cracking and cutting of the electrode.

  In addition, a positive electrode active material layer provided on one surface of the positive electrode current collector layer is configured to be divided into a plurality of active material layer units at regular intervals by a plurality of recesses, and the positive electrode is mounted. An example of a technique related to a battery is disclosed (for example, see Patent Document 2). Since the portion corresponding to the concave portion of the positive electrode current collector layer is used as a fulcrum and can be bent up to a bending angle at which the active material layer units hit each other, the flexible characteristics of the battery equipped with the positive electrode are improved.

  Furthermore, the first step of applying and forming a portion where the thickness of the positive electrode mixture paint or the negative electrode mixture paint becomes thin, and the positive electrode mixture paint or the negative electrode mixture paint were dried on at least one place of the current collector Thereafter, the active material density of the electrode plate is changed to the inner peripheral surface and outer periphery of the electrode group through a second step of forming a portion having a low active material density in at least one portion of the positive electrode plate or the negative electrode plate. An example of a technique related to a non-aqueous secondary battery that is partially small in terms of surface is disclosed (see, for example, Patent Document 3).

JP-A-10-154506 JP 2002-343340 A JP 2009-181833 A

  However, when the technique of Patent Document 1 is applied and the electrode is wound and then pressed and formed into a flat shape, the curvature radius greatly changes at the bent portion, so that there are problems such as cracking, cracking and cutting of the electrode. May occur. That is, since the streak is only about 1/10 to 1/3 of the thickness of the electrode, cracks, cracks, cuts, etc. due to compression occur on the inner peripheral surface side of the bent portion, and extension occurs on the outer peripheral surface side of the bent portion. Accompanied by cracks, cracks, cuts, etc.

  Even when the technique of Patent Document 2 is applied, the bending angle when the positive electrode is wound and then pressed to form a flat shape is large, and in particular, the innermost positive electrode has a bending angle much larger than 90 degrees. become. When the pressing is performed so as to have such a bending angle, the active material layer units come into contact with each other, so that the positive electrode active material layer is cracked, cracked, cut, or the like.

  Furthermore, in the technique of Patent Document 3, not only intermittent coating control (first step) but also active material density change control (second step) must be performed in parallel. It is difficult to improve. When a flat body is formed by winding and pressing the electrode plate, the radius of curvature changes according to the number of turns (also referred to as “number of ridges”, “number of layers”, and so on). In the second step, it is necessary to perform control to change the active material density according to the radius of curvature, and in the subsequent steps, the electrodes must be cut at an accurate interval. Therefore, the probability of becoming a defective product increases, and the yield deteriorates.

  The present invention has been made in view of the above points, and prevents defects such as cracking, cracking, and cutting of the electrode plate even if the electrode plate is rolled and then pressed into a flat shape. An object of the present invention is to provide a wound battery, a manufacturing method thereof, and a manufacturing apparatus.

  The invention according to claim 1, which has been made to solve the above-described problems, includes a positive electrode plate and a negative electrode plate each having an electrode active material layer formed on a strip-shaped current collector, and the positive electrode plate and the negative electrode plate. An insulating separator interposed between the positive electrode plate, the negative electrode plate and the separator, wound and laminated, and obtained by a flat press that presses the wound body formed by the winding into a flat shape In a wound battery having a flat body (that is, a flat electrode body), one or both of the positive electrode plate and the negative electrode plate are the electrode active material in a portion that becomes a bent portion of the flat body. A groove-like groove-shaped portion formed along the short-side direction on the inner peripheral surface side, and the electrode active material layer in a portion to be a bent portion of the flat body, the short-side on the outer peripheral surface side Cut portion formed along the direction or the groove-like portion And having one or both Of.

  According to this configuration, the electrode active material layer on the inner peripheral surface side is formed with a groove portion, and the electrode active material layer on the outer peripheral surface side is used with an electrode plate in which a cut portion or a groove portion is formed. Winding and flat pressing are performed to form a wound battery. Even when flat pressing is performed, the groove portion on the inner peripheral surface side prevents the electrode active material layer from being compressed, and the electrode active material layer is elongated at the cut portion and groove portion on the outer peripheral surface side. To prevent. By forming it on one or both of the inner peripheral surface side and the outer peripheral surface side, it is possible to prevent problems such as cracking, cracking, and cutting of the electrode plate (particularly the electrode active material layer) from the prior art.

  Note that the “current collector” is formed of a conductive material (including a substance; the same applies hereinafter) in a band shape (long sheet shape), but the plate thickness is arbitrary. The “separator” is a member that prevents the positive electrode plate and the negative electrode plate from coming into contact with each other, and includes, for example, an insulating plate material or a solid electrolyte. The “electrode active material layer” is also called a mixture layer, and the positive electrode active material layer and the negative electrode active material layer are made of different materials. The positive electrode active material layer is made of a material such as a metal sulfide, a metal oxide, or a polymer compound capable of inserting and extracting light metal ions such as lithium ions. The negative electrode active material layer is made of, for example, a light metal such as lithium (Li) or sodium (Na), an alloy containing these light metals, or a material capable of inserting and extracting light metals. The cross-sectional shape of the “grooved portion” is arbitrary, but considering the point that is formed into a flat shape by the flat pressing process, the shape that opens toward the end surface (for example, V shape, U shape, box shape, etc.) desirable. The “short-side direction” means a width direction that intersects the long-side direction of the current collector and a direction along the surface.

  According to a second aspect of the present invention, one or both of the groove-shaped portion and the cut portion are formed at unequal intervals (also referred to as “non-equal intervals”; hereinafter the same). Features. As the electrode plate continues to be wound (when the number of turns increases), the radius of curvature of the groove-like portion or notch portion to be formed also changes. Therefore, it is desirable to form them at unequal intervals in order to suppress the tensile force generated between the groove-shaped part and the notch part below a certain value. According to this configuration, since the groove portions and the cut portions are formed at unequal intervals, the tensile force between the groove portions and the cut portions can be suppressed to a predetermined value or less. Therefore, it is possible to more reliably prevent the electrode plate from having defects such as irregularities, cracks, cracks, and cutting.

  According to a third aspect of the present invention, there is provided a positive electrode plate and a negative electrode plate each having an electrode active material layer formed on a strip-shaped current collector, and an insulating separator interposed between the positive electrode plate and the negative electrode plate. In the manufacturing method of a wound type battery for manufacturing a wound type battery comprising: a winding step in which the positive electrode plate, the negative electrode plate and the separator are stacked and wound, and a winding formed by the winding step A flat pressing step for pressing the body into a flat shape and performed before the winding step, and formed by the flat pressing step on one or both of the positive electrode plate and the negative electrode plate. An inner peripheral surface side processing step of forming a groove-shaped groove-shaped portion along the short side direction on the inner peripheral surface side of the electrode active material layer in a portion to be a bent portion of a flat body, and the flat pressing step Site to be a bent part of the formed flat body One or both of the processing steps of the electrode active material layer and the outer peripheral surface side processing step for forming the cut portion or the groove-shaped portion cut along the short side direction on the outer peripheral surface side. Features.

  According to this configuration, the groove-shaped portion is formed in the electrode active material layer. Even when the electrode plate is wound in the winding step and further pressed in the flat pressing step, the electrode active material layer is prevented from being compressed by the groove-shaped portion formed in the electrode active material layer. Therefore, it is possible to prevent problems such as cracking, cracking, and cutting of the electrode plate (particularly, the electrode active material layer on the inner peripheral surface side). In addition, when performing both an "inner peripheral surface side processing process" and an "outer peripheral surface side processing process", you may perform in parallel and may perform in order before and after.

  The invention described in claim 4 is characterized in that, after performing the machining step, there is a machining waste removing step of removing machining waste generated along with the formation of the groove-shaped portion or the cut portion. According to this configuration, since the processing waste is removed during or after the processing of the groove-shaped portion or the cut portion, the processing waste is sandwiched between the electrode plates, and the electrode plate is uneven, cracked, cracked, cut, etc. Can be prevented from occurring.

  According to a fifth aspect of the present invention, each of the processing steps is a period from when the electrode active material layer is formed on the current collector to before pressing (hereinafter referred to as “pre-press period”). A period from the press to before cutting into a predetermined shape (hereinafter referred to as “pre-cutting period”), a period from the cutting to before winding (hereinafter referred to as “pre-winding period”). ) Within one or more periods. According to this configuration, the inner peripheral surface side machining step is performed within one or more periods among the pre-press period, the pre-cut period, and the pre-winding period. That is, it may be performed within one period, or may be performed within a plurality (two or three) periods. The same applies to the outer peripheral surface side machining step. In the inner peripheral surface side machining step, the groove portion can be reliably formed, and in the outer peripheral surface side machining step, the cut portion or the groove portion can be reliably formed. When it is performed within a plurality of periods, the same part (including a part thereof) is processed to ensure the formation of the groove part and the cut part, and the different part is processed to form the groove part and the cut part. The number of formation sites can be increased.

  The invention described in claim 6 is characterized in that the processing step forms the groove portion or the cut portion in the electrode plate corresponding to a portion of the flat body up to a predetermined round. Since the radius of curvature is small at the part up to a predetermined number of turns (also called “number of powers”, the same shall apply hereinafter), defects such as cracking, cracking, and cutting of the electrode plate (especially the electrode active material layer) must be taken without any measures. May occur. According to this configuration, since the groove portion or the cut portion is formed in the electrode plate (specifically, the electrode active material layer) corresponding to the portion up to the predetermined turn, the electrode plate is cracked, cracked, cut, etc. Can be prevented from occurring. The “predetermined number of turns” varies depending on the thicknesses of the current collector and the electrode active material layer, but is, for example, 1 to 3 [times].

  The invention according to claim 7 is characterized in that in the processing step, the groove portion or the cut portion is formed in the electrode plate corresponding to a portion having a predetermined radius of curvature or less in the flat body. And If no measures are taken at a portion where the radius of curvature is equal to or less than a predetermined radius of curvature, problems such as cracking, cracking, and cutting of the electrode plate (particularly the electrode active material layer) may occur. According to this configuration, since the groove portion or the cut portion is formed in the electrode plate (specifically, the electrode active material layer) corresponding to a portion having a predetermined radius of curvature or less, the electrode plate is cracked or cracked. , Cutting and other problems can be prevented. The “predetermined radius of curvature” varies depending on the thicknesses of the current collector and the electrode active material layer, but is, for example, 0 to 600 [μm].

  The invention described in claim 8 is characterized in that in the processing step, the groove portions or the cut portions are formed at unequal intervals. As the electrode plate continues to be wound (when the number of turns increases), the radius of curvature of the groove-like portion and the cut portion to be formed also changes. In order to suppress the tensile force generated between the groove-shaped part and the notch part to a certain value or less after winding, it is desirable to form them at unequal intervals. According to this configuration, the groove portions are formed at unequal intervals in the inner peripheral surface side processing step, and the cut portions or groove portions are formed at unequal intervals in the outer peripheral surface side processing step. Therefore, since the tensile force between the groove-shaped part and the notch part can be suppressed to a certain value or less, it is possible to more reliably prevent the electrode plate from having problems such as irregularities, cracks, cracks, and cutting.

  The invention described in claim 9 is characterized in that, in the processing step, an interval for forming the groove portion or the cut portion is changed based on a radius of curvature applied to a bent portion of the flat body. According to this configuration, since the tensile force between the groove-shaped part and the notch part is dispersed and kept below a certain value after winding, problems such as irregularities, cracks, cracks, and cutting occur on the electrode plate. Can be more reliably prevented.

  According to a tenth aspect of the present invention, in the processing step, the groove shape is formed with respect to the electrode plate at a position where an imaginary line radially extending from a central point applied to the bent portion of the flat body and the electrode plate intersect. It forms in a part or the said notch part, It is characterized by the above-mentioned. According to this configuration, since the groove-shaped portion and the cut portion corresponding to the radius of curvature are formed, the tensile force between the groove-shaped portion and the cut portion is made uniform after winding, and the electrode plate is uneven. It is possible to more reliably prevent defects such as cracks, cracks, and cutting. The “virtual line” can set an arbitrary line segment and includes not only a straight line but also a curved line or a broken line.

  The invention described in claim 11 is characterized in that the processing step forms the groove-shaped portion having a V-shaped cross section. According to this configuration, since the groove-shaped portion is formed in a V shape, it is difficult for the electrode active material layers to hit each other particularly on the inner peripheral surface side. Therefore, it is possible to more reliably prevent defects such as irregularities, cracks, cracks, and cutting on the electrode plate.

  According to a twelfth aspect of the present invention, in the machining step, the groove-shaped portion is formed so that one or both of the V-shaped angle and depth are reduced from the inner peripheral side toward the outer peripheral side. It is characterized by doing. As the radius of curvature increases from the inner peripheral side toward the outer peripheral side, the bending rate of the wound electrode plate decreases. According to this configuration, the angle of the V-shaped groove-shaped portion decreases from the inner peripheral side to the outer peripheral side, so that it is possible to prevent problems such as irregularities, cracks, cracks, and cutting on the electrode plate. In addition, the rigidity of the electrode plate on the outer peripheral side can be increased. The same applies to the case where the depth (depth) of the groove-like portion is reduced.

  The invention according to claim 13 is a positive electrode plate and a negative electrode plate each having an electrode active material layer formed on a strip-shaped current collector, and an insulating separator interposed between the positive electrode plate and the negative electrode plate, In a winding type battery manufacturing apparatus for manufacturing a winding type battery comprising: a winding means for laminating and winding the positive electrode plate, the negative electrode plate and the separator; and a winding formed by the winding means Flat pressing means for pressing the body flatly and before the winding means, and formed by the flat pressing means for one or both of the positive electrode plate and the negative electrode plate. An inner peripheral surface side processing means for forming a groove-like groove-shaped portion along the short side direction on the inner peripheral surface side of the electrode active material layer in a portion to be a bent portion of a flat body, and the flat press means The part to be the bent part of the formed flat body One or both of the electrode active material layer and the outer peripheral surface side processing means for forming the cut portion or the groove-shaped portion cut along the short side direction on the outer peripheral surface side. It is characterized by. According to this configuration, it is possible to prevent problems such as cracking, cracking, and cutting of the electrode plate (particularly the electrode active material layer) as in the case of the third aspect.

  The invention described in claim 14 is characterized in that it has a processing waste removing means for removing processing waste generated along with the formation of the groove-shaped portion or the cut portion. According to this configuration, as in the invention described in claim 4, since the machining waste is removed, defects such as irregularities, cracks, cracks, cutting, etc. are formed in the electrode plate due to the processing waste being sandwiched between the electrode plates. Can be prevented.

It is a side view which shows the structural example of an electrode plate typically. It is a top view which shows the structural example of an electrode plate typically. It is a chart figure showing the 1st manufacturing method of a winding type battery. It is a side view which shows an example of a process process. It is a side view which shows typically an example of the site | part which forms a groove-shaped part and a notch part. It is a side view which shows the example which sets the space | interval of a groove-shaped part and a notch part. It is a side view which shows the example which changes the angle and depth of a groove-shaped part. It is a side view which shows an example of a winding process. It is a side view which shows an example of a flat press process. It is a side view which shows typically the flat body after flat press. It is a chart figure showing the 2nd manufacturing method of a winding type battery.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, each figure shows the element required in order to demonstrate this invention, and does not show all the actual elements. When referring to directions such as up, down, left and right, the description in the drawings is used as a reference. “Material” includes substances. When it is simply referred to as “electrode plate”, it means one or both of a positive electrode plate and a negative electrode plate.

  First, a configuration example of an electrode plate that is the basis of a wound battery will be described with reference to FIGS. 1 and 2. About the structural example of an electrode plate, a side view is typically shown in FIG. 1, and a top view is typically shown in FIG. 1A shows a state before winding, FIG. 1B shows a state after winding, and FIG. 1C shows a state after flat pressing. 2A shows the outer peripheral surface after winding, and FIG. 2B shows the inner peripheral surface after winding.

  An electrode body (a flat body to be described later) that is a constituent element of a wound battery is obtained by winding a band-shaped electrode plate into a spiral shape and further pressing it into a flat shape. FIG. 1 and FIG. 2 show a part centered on a bent portion for easy viewing. The positive electrode plate and the negative electrode plate of the wound battery according to this embodiment are only different in positive and negative. Therefore, the positive electrode plate will be described as a representative, and the content different from the positive electrode plate will be described for the negative electrode plate.

  In the positive electrode plate 10 shown in FIG. 1A, positive electrode active material layers 11 and 13 are formed on the surface of a positive electrode current collector 12 having a strip shape. The positive electrode current collector 12 is formed in a strip shape from a conductive material (for example, metal or conductive plastic). The thickness is set in accordance with the specifications of the wound battery to be manufactured (for example, storage capacity, outer dimensions, etc.), and is, for example, about 5 to 300 [μm]. The negative electrode plate may have the same thickness as the positive electrode plate 10 or a different thickness. The same applies to the shape, for example, a flat plate shape, a foil shape, a net shape, or the like. The positive electrode active material layer 11 is formed on the outer peripheral surface side after winding, and the positive electrode active material layer 13 is formed on the inner peripheral surface side after winding.

  The positive electrode active material layers 11 and 13 are made of a material such as a metal sulfide, a metal oxide, or a polymer compound that can occlude / release light metal ions such as lithium ions. Although not shown, the negative electrode active material layer formed on the surface of the negative electrode current collector constituting the negative electrode plate can occlude / release light metals such as lithium and sodium, alloys containing these light metals, or light metals. Consists of possible materials.

  A groove-shaped portion or a cut portion is formed in the positive electrode plate 10 at a portion corresponding to the bent portion B after flat pressing. Specifically, a cut portion 11 a (or groove-shaped portion) is formed in the positive electrode active material layer 11, and a groove-shaped portion 13 a is formed in the positive electrode active material layer 13. The cut portion 11 a and the groove-like portion 13 a are formed within the range of the positive electrode active material layer and are not formed on the positive electrode current collector 12.

  If the insulating separator 30 is interposed between the positive electrode plate 10 and the negative electrode plate 20 in which the above-described cut portion 11a and groove-like portion 13a are formed (see FIG. 8), FIG. ) Is formed. However, FIG. 1B shows a configuration focusing only on the positive electrode plate 10. Compared with the configuration shown in FIG. 1A, the gap between the groove-like portions 13a on the inner peripheral surface side is reduced with winding, and the cut portions 11a on the outer peripheral surface side expand in a V shape.

  Further, when the wound body 100 described above is flat pressed (see FIG. 9), a flat body 200 is formed as a flat electrode body as shown in FIG. FIG. 1C shows a structure in which only the positive electrode plate 10 is focused, as in FIG. Compared with the configuration of FIG. 1C, the groove portion 13a on the inner peripheral surface side is almost free of gaps with bending, and the end surface side of the cut portion 11a on the outer peripheral surface side further expands. In the bending by the flat press, the groove portion 13a avoids (or absorbs) compression, and the cut portion 11a avoids (or absorbs) extension. Therefore, the positive electrode active material layers 11 and 13 are not cracked, cracked or cut. The same applies to the case where a cut portion or a groove-like portion is formed in the negative electrode plate 20 in the same manner as the positive electrode plate 10, and winding and bending are performed.

  When the belt-like positive electrode plate 10 is viewed in plan, the structure shown in FIG. 2 is obtained. FIG. 2A and FIG. 2B are states reversed in the left-right direction. The electrode plate is cut at a plate width W (in addition, plate length, plate thickness, etc.) by a cutting step (steps S15 and S23 shown in FIG. 3) described later. The positive electrode plate 10 has a portion where the positive electrode active material layer 11 is not formed on the upper side of the drawing in FIG. 2A, and a portion where the positive electrode active material layer 13 is not formed on the upper side of the drawing in FIG. In other words, there is a portion of only the positive electrode current collector 12. The portion having only the positive electrode current collector 12 is used to electrically connect the positive electrode current collectors 12 to each other after performing a flat pressing step (step S32 shown in FIG. 3) described later. The same applies to the negative electrode current collector 22 of the negative electrode plate 20.

  Next, a process of manufacturing a wound battery by stacking the positive electrode plate 10, the negative electrode plate 20, the separator 30 and the like will be described with reference to FIG. 3 includes a first step of forming the positive electrode plate 10, a second step of forming the negative electrode plate 20, a stack of separators 30 together with the formed positive electrode plate 10 and negative electrode plate 20, and winding. This can be broadly divided into the third step of flat pressing. Below, it demonstrates in order of a 1st process to a 3rd process.

(First Step) Formation Step of Positive Electrode Plate 10 First, a kneading step is performed to produce a kneaded product of the positive electrode active material layers 11 and 13 formed on the positive electrode current collector 12 [Step S10]. The kneaded product is a product obtained by mixing a binder 10a, a positive electrode active material 10b, a conductive material 10c, a solvent 10d, and the like into a liquid or paste form.

  Any binder can be used for the binder 10a. For example, polyvinylidene fluoride (PVDF), a modified body of polyvinylidene fluoride, polytetrafluoroethylene (PTFE), a rubber particle binder having an acrylate unit, and the like are applicable. In addition, you may mix the acrylate monomer which introduce | transduced the reactive functional group, an acrylate oligomer, etc.

The positive electrode active material 10b is made of a material capable of inserting and extracting light metal ions such as lithium ions. Specifically, metal sulfides, metal oxides, polymer compounds, and the like are applicable. Examples of metal sulfides and metal oxides include those that do not contain lithium, such as titanium sulfide (TiS ₂ ), molybdenum sulfide (MoS ₂ ), niobium selenide (NbSe ₂ ), or vanadium oxide (V ₂ O ₅ ). It is done. Examples of the metal oxide include lithium composite oxides represented by Li _x MO _{y in} addition to the above-described substances not containing lithium. Note that M is one or more of cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), zinc (Zn), chromium (Cr), Al, Co, Ni, Ti, and Si. It is a metallic element or a nonmetallic element such as phosphorus (P) or boron (B), and may be used in combination of two or more. As for the subscripts of the composition formula, it is desirable to set x in the range of 0.05 ≦ x ≦ 2.0 and y in the range of 2 ≦ y ≦ 4.

  As the positive electrode active material 10b, it is desirable to use a lithium composite oxide such as lithium / cobalt composite oxide or lithium / nickel oxide in order to ensure high voltage and high energy density and improve cycle characteristics. Two or more of the metal sulfides and metal oxides described above may be used in combination. The material used for the positive electrode active material 10b can be arbitrarily selected according to the type and use of the battery.

For the conductive material 10c, for example, a conductive material such as carbon black is used. It is desirable to use carbon black having a high specific surface area of 30 [m ² / g] or more by a BET method.

  A solvent suitable for kneading is used as the solvent 10d. For example, 1,2-dimethoxyethane, 1,2-diethoxyethane, propylene carbonate, butylene carbonate, ethylene carbonate, γ-butyrolactone, tetrahydrofuran, 1,3-dioxolane, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, etc. A solvent, a mixed solvent in which two or more of these solvents are selected and mixed, and the like are applicable.

  A coating / drying step of forming the kneaded material produced in step S10 as the positive electrode active material layers 11 and 13 on the positive electrode current collector 12 is performed [step S11]. Specifically, after the kneaded material is coated on the positive electrode current collector 12, it is dried at a predetermined temperature to be solidified. Examples of the coating include painting, painting, spraying, and the like. The coating amount of the positive electrode active material layers 11 and 13 is adjusted so as to have a predetermined thickness (for example, 100 to 300 [μm]) after drying. The thickness of the positive electrode current collector 12 is, for example, about 10 to 20 [μm]. In this way, a strip-like positive electrode plate 10 is formed.

  An inner peripheral surface side processing step and an outer peripheral surface side processing step are performed on one or both of the positive electrode plate 10 and the negative electrode plate 20 formed in step S11 [step S12]. The inner peripheral surface side processing step is an electrode active material layer at a portion to be a bent portion B of the flat body 200 formed by a flat pressing step described later, and is along the short side direction (width direction) on the inner peripheral surface side. Thus, the groove 13a is formed in a straight line and a solid line. In the outer peripheral surface side processing step, the cut portions 11a (or groove portions) are formed in a straight line and a solid line along the short side direction (width direction) of the electrode active material layer on the outer peripheral surface side.

  The inner peripheral surface side processing step and the outer peripheral surface side processing step may be performed in parallel, or may be performed sequentially in order. An example performed in parallel is shown in FIG. 4A, and examples performed in order before and after are shown in FIGS. 4B to 4D. In the processing example shown in FIG. 4A, processing is performed on both surfaces of the electrode plate by the processing means 40. That is, the inner peripheral surface side processing means 40b processes the inner peripheral surface side on which the positive electrode active material layer 13 is formed, and the outer peripheral surface side processing means 40a processes the outer peripheral surface side on which the positive electrode active material layer 11 is formed. The inner peripheral surface side processing means 40b can apply any means capable of processing the groove-shaped portion 13a, and the outer peripheral surface-side processing means 40a can be a cut portion 11a or a groove-shaped portion (for example, the groove-shaped portion 11c shown in FIG. 4D). Etc.) can be applied to any means. The groove forming means 43 is used for processing the groove-shaped part 13a (and the groove-shaped part formed in the positive electrode active material layer 11), and the notch forming means 41 is used for processing the notched part 11a. The groove forming means 43 uses a machine tool capable of grooving, such as a shaper or a milling machine. The notch forming means 41 uses, for example, a machine tool capable of being cut by a rotational motion or a reciprocating motion, a laser processing machine, a water jet processing machine (water cutter), or the like.

  In the processing examples shown in FIG. 4B to FIG. 4D, processing is performed for each side of the electrode plate fixed to the flat table 42. For example, the positive electrode plate 10 is first fixed so that the positive electrode active material layer 11 on the outer peripheral surface side becomes the upper surface, and then cut into the positive electrode active material layer 11 by the cut forming means 41 as shown in FIG. The part 11b is processed. Then, after the positive electrode plate 10 is turned over and fixed, the groove-shaped portion 13 a is processed into the positive electrode active material layer 13 by the groove forming means 43 as shown in FIG.

  You may process in the reverse order to the procedure mentioned above. For example, first, the positive electrode plate 10 is fixed so that the positive electrode active material layer 13 on the inner peripheral surface side becomes the upper surface, and then the groove-shaped portion 43 a is processed by the groove forming means 43. Then, after the positive electrode plate 10 is turned over and fixed, the groove-shaped portion 11 c is processed into the positive electrode active material layer 11 by the groove forming means 43 as shown in FIG.

  Moreover, the site | part (position) and shape (angle and depth) which form the groove-shaped part 13a and the notch | incision part 11a mentioned above are demonstrated, referring FIGS. In FIG. 5, an example of the site | part which forms a groove-shaped part and a notch part is typically shown with a side view. In FIG. 6, the example which sets the space | interval of a groove-shaped part and a notch part is shown with a side view. In FIG. 7, the example which changes the angle and depth of a groove-shaped part is shown with a side view.

  FIG. 5 shows an example of the part which forms a groove-shaped part and a notch part by a hatching hatching based on a predetermined circumference and a radius of curvature. FIG. 5 (A) shows a part A1 of the electrode plate corresponding to the bent portion B up to a predetermined number of rounds (for example, 1 to 3 [times]) in the flat body 200. FIG. 5B shows a portion A2 of the electrode plate that is equal to or less than a predetermined curvature radius Rx (for example, 0 to 600 [μm]) in the flat body 200 and corresponds to the bent portion B.

  FIG. 6 shows the interval between the groove-shaped part and the notch part formed in the electrode plate corresponding to the bent part B of the flat body 200. In FIG. 6A, the intervals D1a, D1b, D1c,... Of the notches 11a formed in the positive electrode active material layer 11 on the outer peripheral surface side of the positive electrode plate 10 are set to be unequal intervals (that is, non-uniform). An example is shown in which the intervals D2a, D2b, D2c, D2d,... Of the groove-shaped portion 13a formed in the positive electrode active material layer 13 on the peripheral surface side are set at unequal intervals. In addition, since the notch part 11a and the groove-shaped part 13a which are shown with a dashed-two dotted line are outside the range of the bending part B, it does not ask | require whether it forms.

  6B, the intervals D1a, D1b, D1c,... And the intervals D2a, D2b, D2c, D2d,... Are changed based on the radius of curvature applied to the bent portion B of the flat body 200. An example is shown. Since the curvature and the radius of curvature are inversely related, the curvature radius decreases as the curvature increases, and the curvature radius increases as the curvature decreases. Therefore, the interval at which the groove 13a or the notch 11a is formed is based on the curvature of the position where the notch 11a or the groove 13a is formed (hereinafter simply referred to as “formation position”). Radius R1, R2, R3,... (Namely, a radius of curvature) from the center point Pr of B to the formation position is obtained, and an interval is set according to the ratio of the radius of curvature. For example, the distances D1a, D1b, and D1c shown in FIG. 6A can be expressed by an expression such as “D1a: D1b: D1c = R1: R2: R3”.

  In FIG. 6C, the groove-like portion 13a and the positive electrode plate 10 at positions where the virtual plates L1, L2, L3,... Radially extending from the center point Pr of the bent portion B intersect the positive electrode plate 10 are shown. The example which forms the notch part 11a is shown. That is, positions P1a, P1b, P1c,... Where virtual line L1 and positive electrode plate 10 intersect, positions P2a, P2b, P2c,... Where virtual line L2 and positive electrode plate 10 intersect, virtual line L3 and positive electrode plate 10 Are formed on the positive electrode plate 10 corresponding to the positions P3a, P3b, P3c,. Since the positive electrode plate 10 is wound in a spiral shape, the intervals D1a, D1b, D1c,... And the intervals D2a, D2b, D2c, D2d,.

  FIG. 7 shows an example in which the V-shaped groove-like portion 13a is formed by changing the angle and depth from the inner peripheral side toward the outer peripheral side. FIG. 7A shows a groove-like portion 13a formed in the innermost positive electrode plate 10 in the bent portion B. FIG. The groove 13a is formed with an angle θ1 and a depth D3. FIG. 7B shows an example of the groove-like portion 13a formed with a smaller angle θ2 (that is, θ2 <θ1) toward the outer peripheral side. FIG. 7C shows an example of the groove-like portion 13a formed with a depth D4 shallower (that is, D4 <D3) toward the outer peripheral side. Although not shown, the groove 13a may be formed by reducing both the angle θ2 and the depth D4 toward the outer peripheral side.

  Returning to FIG. 3, in parallel with the inner peripheral surface side processing step and the outer peripheral surface side processing step, or after performing these processing steps, a processing scrap removal step is performed [step S <b> 13]. In the inner peripheral surface side processing step and the outer peripheral surface side processing step, since processing waste is generated during processing, the processing waste removal step is performed to remove the processing waste. The removal method of processing waste is arbitrary. For example, it may be performed by various methods such as flowing with a liquid (water, oil, etc.), blowing off with a gas (air, nitrogen, etc.), and sweeping out using a cleaning member (brush, mop, etc.).

  Thereafter, a pressing step (step S14) for pressing the positive electrode plate 10 with a press machine (for example, a roller) and a cutting step for cutting the positive electrode plate 10 into a predetermined shape (plate length, plate thickness, plate width, etc.) with a cutting machine [ Step S15] is performed in any order. In this way, the positive electrode plate 10 having the groove-like portion 13a and the cut portion 11a and capable of being wound is formed.

(2nd process) Formation process of the negative electrode plate 20 The kneading | mixing process which produces the kneaded material of the negative electrode active material layers 21 and 23 formed in the negative electrode collector 22 is performed [step S20]. The kneaded product is a product obtained by kneading the binder 20a, the negative electrode active material 20b, the dispersion material 20c, the solvent 20d, and the like.

  The binder 20a can use arbitrary binders similarly to the binder 10a. For example, polyvinylidene fluoride (PVDF) or a modified product thereof is applicable. In order to improve the lithium ion acceptability, styrene-butadiene copolymer rubber particles (SBR) and modified products thereof may be used in combination with cellulose resins such as carboxymethyl cellulose (CMC) or in small amounts. Is desirable.

The negative electrode active material 20b is composed of a light metal, an alloy containing the light metal, a material capable of inserting and extracting the alloy and the light metal itself, and the like. Examples of the light metal include lithium (Li) and sodium (Na). Examples of the material capable of inserting and extracting light metals include carbon materials, silicon (Si), silicon compounds, metal oxides, and polymer compounds. Examples of the carbon material include pyrolytic carbons, cokes, graphites, glassy carbons, organic polymer compound fired bodies, carbon fibers, and activated carbon. Examples of the coke include pitch coke, needle coke, and petroleum coke. Glassy carbons include non-graphitizable carbon materials. The organic polymer compound fired body is a carbonized substance obtained by firing a polymer compound (for example, phenol resin or furan resin) at a high temperature (for example, about 500 ° C. or more) in an inert gas stream or in a vacuum. Examples of the silicon compound include CaSi ₂ and CoSi ₂ . An example of the metal oxide is tin oxide (SnO ₂ ). Examples of the polymer compound include polyacetylene and polypyrrole. The material used as the negative electrode active material 20b can be arbitrarily selected according to the type and application of the battery.

  The dispersing material 20c is arbitrary, and for example, N-methyl-2-pyrrolidone (NMP) or the like is used. As the solvent 20d, a solvent suitable for kneading is used similarly to the solvent 10d. The same material as the solvent 10d may be used, or a different material may be used.

  The insulating separator 30 can be formed from a polymer material (particularly porous). The thickness of the separator 30 is, for example, in the range of 10 to 30 [μm]. Examples of the polymer material include polypropylene, polyethylene, and polymethylpentene. Furthermore, you may use the nonwoven fabric formed from these polymeric materials, the film | membrane which made the stretch porous, etc.

  Similarly to step S11, a coating / drying process for forming the kneaded material prepared in step S20 as the negative electrode active material layers 21 and 23 on the negative electrode current collector 20e is performed [step S21]. Specifically, after the kneaded material is coated on the negative electrode current collector 20e, it is dried and solidified at a predetermined temperature. The coating amount of the negative electrode active material layers 21 and 23 is adjusted so as to have a predetermined thickness (for example, 100 to 200 [μm]) after drying. The thickness of the negative electrode current collector 20e is, for example, about 10 to 20 [μm]. In this way, a strip-like negative electrode plate 20 is formed.

  An inner peripheral surface side processing step and an outer peripheral surface side processing step are performed on one or both of the negative electrode plate 20 and the negative electrode plate 20 formed in step S21 as necessary [step S22]. When the plate thickness of the negative electrode plate 20 is significantly smaller than the plate thickness of the positive electrode plate 10, the step S22 may be omitted. The contents of the inner peripheral surface side machining step and the outer peripheral surface side machining step are the same as those in step S12 described above. A groove-shaped portion corresponding to the groove-shaped portion 13a and a cut portion corresponding to the cut portion 11a are formed. When the inner peripheral surface side machining step and the outer peripheral surface side machining step are performed, the machining waste removal step is performed in the same manner as in step S13 [step S23].

  Thereafter, a pressing step [step S24] for pressing the negative electrode plate 20 in the same manner as in step S14, and a cutting step in which the negative electrode plate 20 is cut into a predetermined shape (plate length, plate thickness, plate width, etc.) in the same manner as in step S15. [Step S25] is performed in any order. In this way, the negative electrode plate 20 having a groove-like portion and a cut portion and capable of being wound is formed.

(Third Step) Winding and Flat Pressing After the positive electrode plate 10 and the negative electrode plate 20 are formed, a winding step is performed in which the positive electrode plate 10, the negative electrode plate 20, the separator 30 and the like are stacked and wound in a spiral shape [ Step S31], a flat pressing step of pressing the wound body 100 formed by the winding step into a flat shape is performed [Step S32].

  In step S31, as shown in FIG. 8, the positive electrode plate 10, the negative electrode plate 20, the separator 30 and the like are stacked and wound on the winding means 44. The winding means 44 corresponds to, for example, a columnar or cylindrical roller. When the wound body 100 is removed from the winding means 44, it becomes as shown in FIG.

  In step S32, as shown in FIG. 9, the flat pressing means 46 is moved flat in the direction of arrow D6 with respect to the wound body 100 fixed on the flat table 42. The flat press means 46 corresponds to a press machine having a flat press surface 46a. A flat body 200 obtained by flat pressing is shown in FIG. 10 is an enlarged view of the bent portion B. FIG.

  Here, an example of the electrode plate after flat pressing will be briefly described. Whether or not a problem occurs in the electrode plate (particularly the electrode active material layer) depending on whether or not the groove portion 13a on the inner peripheral surface side and the cut portions 11a and 11b and the groove portion 11c on the outer peripheral surface side are formed. We experimented. The experimental results are shown in Table 1 below. The positive electrode plate 10 used in the experiment was formed using an aluminum foil (Al) having a thickness of 15 [μm] as the positive electrode current collector 12 and having a length of 1.4 [m]. The negative electrode plate 20 was formed using a copper foil (Cu) having a thickness of 10 [μm] as the negative electrode current collector 22 and having a length of 1.5 [m]. The separator 30 was formed with a thickness of 20 [μm] and a length of 1.6 [m]. The total number of laps (total number) is 6 [times]. Regarding the presence or absence of a groove-shaped part or a notch part, an electrode plate having a predetermined circumference of 0 [times], that is, not formed at all, is indicated as “none”, and an electrode plate having a predetermined circumference of 1 [times], that is, formed only on the innermost circumference An electrode plate formed by “1st grid” and having a predetermined turn of 2 [turns], that is, 1 round and 2 rounds, is shown by “1,2 grid”. Regarding the presence / absence of defects, the generated electrode plates are indicated by “x”, and the electrode plates that did not occur are indicated by “◯”.

  According to the embodiment described above, the following effects can be obtained. First, according to claim 1, in the wound battery, one or both of the positive electrode plate 10 and the negative electrode plate 20 is an electrode at a portion to be a bent portion B of the flat body 200 formed by flat pressing. The active material layer is an electrode active material layer in a portion that becomes a groove-like groove-shaped portion 13a formed along the short side direction on the inner peripheral surface side and a bent portion B of the flat body 200 formed by flat pressing. And it was set as the structure provided with both the notch parts 11a and 11b or the groove-shaped part 11c formed along the short side direction of an outer peripheral surface side (refer FIG.1 (C) and FIG.4 (D)). . According to this configuration, even when flat pressing is performed, the groove portion 13a on the inner peripheral surface side prevents the positive electrode active material layer 13 and the negative electrode active material layer 23 from being compressed, and the cut portion on the outer peripheral surface side. 11a, 11b and the groove-like portion 11c prevent the positive electrode active material layer 11 and the negative electrode active material layer 21 from being elongated. By forming it on one or both of the inner peripheral surface side and the outer peripheral surface side, it is possible to prevent problems such as cracking, cracking, and cutting of the electrode plate (particularly the electrode active material layer) from the prior art. In addition, it is good also as a structure provided with either one of the groove-shaped part 13a formed in an inner peripheral surface side, and the notch parts 11a and 11b or the groove-shaped part 11c formed in an outer peripheral surface side. Even if it is this structure, the said effect can be obtained about each surrounding surface side.

  Corresponding to claim 2, one or both of the positive electrode plate 10 and the negative electrode plate 20 is configured to form the groove portions 13 a or the cut portions 11 a at unequal intervals (see FIG. 1). . According to this configuration, since the tensile force between the groove-like portion 13a and the notch portion 11a is suppressed to a certain value or less, it is more reliable that defects such as irregularities, cracks, cracks, and cutting occur on the electrode plate. Can be prevented.

  Corresponding to claims 3 and 13, a winding step (winding means 44) for laminating and winding the positive electrode plate 10, the negative electrode plate 20 and the separator 30, and the winding body 100 formed by the winding step is flattened. The flat pressing step (flat pressing means 46) that presses into a shape is performed before the winding step, and is formed by one or both of the positive electrode plate 10 and the negative electrode plate 20 by the flat pressing step. Inner peripheral surface side processing step (inner peripheral surface) for forming a groove-shaped groove-shaped portion 13a along the short side direction on the inner peripheral surface side of the electrode active material layer at the portion to be the bent portion B of the flat body 200 Side processing means 40b) and an electrode active material layer in a portion to be a bent portion B of the flat body 200, and the outer peripheral surface side forming the cut portion 11a or the groove portion 11c along the short side direction on the outer peripheral surface side One of the machining steps (outer peripheral surface side machining means 40a) And configured to have a both a processing step (see FIGS. 1-9). According to this configuration, the electrode active material layer is prevented from being compressed by the groove-shaped portion 13 a formed in the positive electrode active material layer 13 or the negative electrode active material layer 23 on the inner peripheral surface side. Further, the electrode active material layer is prevented from extending by the cut portions 11a or the groove portions 11c formed in the positive electrode active material layer 11 or the negative electrode active material layer 21 on the outer peripheral surface side. By forming it on one or both of the inner peripheral surface side and the outer peripheral surface side, it is possible to prevent problems such as cracking, cracking, and cutting of the electrode plate (particularly the electrode active material layer) from the prior art.

  Corresponding to claims 4 and 14, after performing one or both of the inner peripheral surface side processing step and the outer peripheral surface side processing step, processing that occurs with the formation of the groove-shaped portion 13a or the cut portion 11a. It was set as the structure which has the processing waste removal process (processing waste removal means) which removes waste. According to this configuration, since the processing waste is removed during or after the processing of the groove-shaped portion 13a or the cut portion 11a, the processing waste is sandwiched between the electrode plates. It is possible to prevent problems such as cutting.

  Corresponding to claim 5, the inner peripheral surface side processing step and the outer peripheral surface side processing step are performed within the pre-press period (see FIG. 3). According to this configuration, the groove portion 13a can be reliably formed in the inner peripheral surface side machining step, and the cut portion 11a or the groove portion 11c can be reliably formed in the outer peripheral surface side machining step. In FIG. 11, the configuration may be performed within the period before winding as shown by the formation of the positive electrode plate 10, or may be configured within the period before cutting as shown by the formation of the negative electrode plate 20. Either configuration is applicable to one or both of the positive electrode plate 10 and the negative electrode plate 20. When performing within a plurality of (two or three) periods, by processing the same part (including a part thereof), it is possible to ensure the formation of the groove-like part 13a and the cut part 11a, and to process different parts. The formation location of the groove-shaped part 13a and the notch part 11a can be increased.

  Corresponding to claim 6, in the inner peripheral surface side processing step and the outer peripheral surface side processing step, the groove-shaped portion 13a or the cut portion 11a is formed on the electrode plate corresponding to the portion A1 up to the predetermined circumference in the flat body 200. (See FIG. 5A). According to this structure, since the groove-shaped part 13a and the notch part 11a are formed in the location where a curvature radius is small, it can prevent that troubles, such as a crack, a crack, a cutting | disconnection of an electrode plate, arise.

  Corresponding to claim 7, the inner peripheral surface side processing step and the outer peripheral surface side processing step are the groove-shaped portion 13a or the notch portion with respect to the electrode plate corresponding to the portion having a predetermined curvature radius Rx or less in the flat body 200. 11a is formed (see FIG. 5B). According to this configuration, since the groove-like portion 13a and the cut portion 11a are formed at a portion that is equal to or smaller than the predetermined curvature radius Rx, it is possible to prevent problems such as cracking, cracking, and cutting of the electrode plate.

  Corresponding to claim 8, the inner peripheral surface side processing step and the outer peripheral surface side processing step are configured to form the groove portions 13a or the cut portions 11a at unequal intervals (see FIG. 6A). According to this configuration, since the tensile force between the groove-like portion 13a and the notch portion 11a is suppressed to a certain value or less, it is more reliable that defects such as irregularities, cracks, cracks, and cutting occur on the electrode plate. Can be prevented.

  Corresponding to claim 9, the inner peripheral surface side processing step and the outer peripheral surface side processing step change the interval for forming the groove-shaped portion 13a or the cut portion 11a based on the radius of curvature applied to the bent portion B of the flat body 200. (See FIG. 6B). According to this configuration, since the tensile force between the groove-like portion 13a and the cut portion 11a is dispersed and suppressed to a certain value or less after winding, the electrode plate has problems such as unevenness, cracks, cracks, and cutting. Can be more reliably prevented.

  Corresponding to claim 10, the inner peripheral surface side processing step and the outer peripheral surface side processing step include virtual lines L1, L2, L3,... Radially extending from the center point Pr applied to the bent portion B of the flat body 200 and the electrode plate. With respect to the electrode plate at a position where and intersect, the groove-shaped portion 13a or the cut portion 11a is formed (see FIG. 6C). According to this configuration, the tensile force between the groove-like portion 13a and the cut portion 11a is made uniform after winding, and it is more reliable that defects such as irregularities, cracks, cracks, and cutting occur in the electrode plate. Can be prevented.

  Corresponding to claim 11, the inner peripheral surface side processing step and the outer peripheral surface side processing step are configured to form a groove-shaped portion 13a having a V-shaped cross section (see FIG. 1, FIG. 4, FIG. 7, etc.). . According to this configuration, since the groove-shaped portion 13a is formed in a V shape, it is difficult for the electrode active material layers to hit each other particularly on the inner peripheral surface side. Therefore, it is possible to more reliably prevent defects such as irregularities, cracks, cracks, and cutting on the electrode plate.

  Corresponding to claim 12, the inner peripheral surface side processing step and the outer peripheral surface side processing step are such that one or both of the V-shaped angle and depth become smaller from the inner peripheral side toward the outer peripheral side. It was set as the structure which forms the groove-shaped part 13a (refer FIG. 7). According to this configuration, it is possible to increase the rigidity of the electrode plate on the outer peripheral side while preventing defects such as irregularities, cracks, cracks, and cutting from occurring in the electrode plate.

[Other Embodiments]
Although the form for implementing this invention was demonstrated above, this invention is not limited to the said form at all. In other words, various forms can be implemented without departing from the scope of the present invention. For example, the following forms may be realized.

  In the embodiment described above, the electrode active material layers (the positive electrode active material layers 11 and 13 and the negative electrode active material layers 21 and 23) are formed on both surfaces of the current collector (the positive electrode current collector 12 and the negative electrode current collector 22). An electrode plate was applied (see FIG. 1 etc.). It can replace with this form and can also apply the electrode plate which formed the electrode active material layer only in the single side | surface of a collector. For example, in the positive electrode plate 10 in which only the positive electrode active material layer 13 is formed on one surface of the positive electrode current collector 12, the groove-shaped portion 13a may be formed by the inner peripheral surface side processing step (inner peripheral surface side processing means 40b). The surface side processing step (outer peripheral surface side processing means 40a) becomes unnecessary. On the other hand, in the positive electrode plate 10 in which only the positive electrode active material layer 11 is formed on one surface of the positive electrode current collector 12, the cut portion 11a and the groove-shaped portion 11c are formed by the outer peripheral surface side processing step (the outer peripheral surface side processing means 40a). The inner peripheral surface side processing step (inner peripheral surface side processing means 40b) is not necessary. The same applies to the negative electrode plate 20 in which the electrode active material layer is formed only on one surface of the negative electrode current collector 22. Since only the formation surface of the electrode active material layer is different, it is possible to obtain the same effect as the above-described embodiment.

  In the above-described embodiment, the kneaded material obtained by kneading the binder 10a, the positive electrode active material 10b, the conductive material 10c, and the solvent 10d is formed as the positive electrode active material layers 11 and 13 on the positive electrode current collector 12 (FIG. 3). , See the coating / drying step shown in steps S11 and S21 of FIG. Instead of this form, the positive electrode current collector 12 is formed by coating the binder 10a, the positive electrode active material 10b, the conductive material 10c, and the solvent 10d in parallel (or in order, before and after) on the positive electrode current collector 12. It is good also as a structure directly formed as the positive electrode active material layers 11 and 13 on it. The same applies when the negative electrode active material layers 21 and 23 are formed on the negative electrode current collector 22. According to this embodiment, since the kneading step is unnecessary, the time required for forming the electrode plate can be shortened.

  In the above-described embodiment, the intervals D1a, D1b, D1c,... And the intervals D2a, D2b, D2c, D2d,. (See FIG. 6B). Instead of this configuration, the interval value may be changed stepwise by maintaining the interval at a constant value with respect to the radius of curvature within a predetermined range. For example, when the radius of curvature is less than 10 [μm], the interval is 50 [μm]. When the radius of curvature is 10 [μm] or more and less than 20 [μm], the interval is 70 [μm], and the radius of curvature is 20 When the distance is not less than [μm] and less than 50 [μm], the interval is set to 100 [μm], and when the radius of curvature is not less than 50 [μm] and less than 100 [μm], the interval is set to 200 [μm]. Even in this configuration, since the tensile force between the groove-like portion 13a and the notch portion 11a is dispersed and kept below a certain value after winding, problems such as unevenness, cracks, cracks, and cutting occur in the electrode plate. Can be more reliably prevented.

  In the embodiment described above, the groove-like portion 13a is formed in a linear V-shape (see FIGS. 1, 4, 7, 10, etc.). It may replace with this form and you may form in the other shape opened toward an end surface. Other shapes are, for example, non-linear (curved or stepped) V-shaped, U-shaped, box-shaped (including stepped), and the like. If it is the shape opened toward an end surface, even if the winding body 100 is pressed flatly by a flat pressing process, the electrode active material layers will not easily hit each other. Therefore, it is possible to more reliably prevent defects such as irregularities, cracks, cracks, and cutting from occurring on the electrode plate.

  In the embodiment described above, the groove-like portion 13a and the cut portion 11a are formed linearly along the short side direction of the current collector. Instead of this form, the groove-like portion 13a and the cut portion 11a may be formed with other planar shapes (that is, a linear processing locus). The other planar shape corresponds to, for example, a curve or a broken line. Regardless of the planar shape, the electrode active material layers are difficult to touch each other, so that defects such as irregularities, cracks, cracks, and cutting can be more reliably prevented from occurring on the electrode plate.

  In embodiment mentioned above, the line segment of the groove-shaped part 13a and the notch | incision part 11a formed along the short side direction of a collector was comprised by the continuous line shape. Instead of this form, the groove-like portion 13a and the cut portion 11a may be configured by other line segments. The other line segment corresponds to a line segment other than a solid line such as a broken line, a one-dot chain line, a two-dot chain line, or the like. When the line segment other than the solid line is formed, the electrode active material layer is compressed or stretched at a portion where the groove-shaped portion 13a or the cut portion 11a is not formed. This compression or stretch is caused by the groove-shaped portion 13a or the cut portion 11a. It can escape to the space part formed. Therefore, it is possible to more reliably prevent defects such as irregularities, cracks, cracks, and cutting from occurring in the electrode plate.

10 Positive plate (electrode plate)
10a, 20a Binder (binder)
10b Positive electrode active material (electrode active material)
10c Conductive material 10d, 20d Solvent 11, 13 Positive electrode active material layer (electrode active material layer)
11a, 11b Cut portion 11c, 13a Groove portion 12 Positive electrode current collector (current collector)
20 Negative electrode plate (electrode plate)
20b Negative electrode active material (electrode active material)
20c Dispersant 21, 23 Negative electrode active material layer (electrode active material layer)
22 Negative electrode current collector (current collector)
30 Separator 40 Processing means 40a Outer peripheral surface side processing means 40b Inner peripheral surface side processing means 41 Notch forming means 43 Groove forming means 44 Winding means 46 Flat pressing means 100 Winding body 200 Flat body B Bending part L1, L2, L3 , ... Virtual line Pr Center point

Claims (14)

A positive electrode plate and a negative electrode plate each having an electrode active material layer formed on a strip-shaped current collector; and an insulating separator interposed between the positive electrode plate and the negative electrode plate. In a wound battery having a flat body obtained by a flat press for laminating and winding a plate and the separator, and pressing the wound body formed by winding into a flat shape,
One or both of the positive electrode plate and the negative electrode plate is the electrode active material layer in a portion that becomes a bent portion of the flat body and is formed along the short side direction on the inner peripheral surface side. Of the groove-shaped groove-shaped portion and the cut portion or the groove-shaped portion formed along the short side direction on the outer peripheral surface side of the electrode active material layer in the portion to be a bent portion of the flat body A wound battery characterized by having one or both.   2. The wound battery according to claim 1, wherein one or both of the groove-shaped portion and the cut portion are formed at unequal intervals. A wound battery comprising a positive electrode plate and a negative electrode plate each having an electrode active material layer formed on a strip-shaped current collector, and an insulating separator interposed between the positive electrode plate and the negative electrode plate is manufactured. In the manufacturing method of the wound battery,
A winding step of laminating and winding the positive electrode plate, the negative electrode plate and the separator;
A flat pressing step for flatly pressing the wound body formed by the winding step;
Prior to the winding step, the electrode activity in a portion that becomes a bent portion of a flat body formed by the flat pressing step with respect to one or both of the positive electrode plate and the negative electrode plate. An inner peripheral surface side processing step of forming a groove-shaped groove-shaped portion along the short side direction on the inner peripheral surface side of the material layer, and a portion to be a bent portion of the flat body formed by the flat pressing step One or both of the processing steps of the electrode active material layer and the outer peripheral surface side processing step for forming the cut portion or the groove-shaped portion cut along the short side direction on the outer peripheral surface side,
A method for producing a wound battery, comprising:   4. The wound battery manufacturing method according to claim 3, further comprising a processing waste removal step of removing processing waste generated along with the formation of the groove-shaped portion or the cut portion after performing the processing step. 5. Method.   Each of the processing steps includes a period from the formation of the electrode active material layer on the current collector to a time before pressing, a period from the pressing to a time before cutting into a predetermined shape, and winding 5. The method for manufacturing a wound battery according to claim 3, wherein the method is performed within one or more of the periods before the start.   The said process process forms the said groove-shaped part or the said notch part with respect to the said electrode plate corresponding to the site | part to the predetermined circumference | surroundings in the said flat body, The any one of Claim 3 to 5 characterized by the above-mentioned. A method for producing the wound battery according to claim 1.   The said processing step forms the said groove-shaped part or the said notch part with respect to the said electrode plate corresponding to the site | part which becomes below a predetermined curvature radius in the said flat body, The any one of Claim 3 to 5 characterized by the above-mentioned. A method for producing a wound battery according to claim 1.   The said manufacturing process forms the said groove-shaped part or the said notch part at unequal intervals, The manufacturing method of the winding type battery as described in any one of Claim 3 to 7 characterized by the above-mentioned.   9. The wound battery according to claim 8, wherein in the processing step, an interval for forming the groove portion or the cut portion is changed based on a radius of curvature applied to a bent portion of the flat body. Production method.   The machining step is formed in the groove portion or the cut portion with respect to the electrode plate at a position where an imaginary line radially extending from a central point applied to the bent portion of the flat body and the electrode plate intersect. The method for manufacturing a wound battery according to claim 8 or 9, wherein:   The method for manufacturing a wound battery according to any one of claims 3 to 10, wherein the processing step forms the groove-shaped portion having a V-shaped cross section.   The said process step forms the said groove-shaped part so that one or both may become small toward the outer peripheral side from an inner peripheral side among the angles and depths which make the said V shape. A method for producing the wound battery according to claim 1. A wound battery comprising a positive electrode plate and a negative electrode plate each having an electrode active material layer formed on a strip-shaped current collector, and an insulating separator interposed between the positive electrode plate and the negative electrode plate is manufactured. In a wound battery manufacturing device,
Winding means for laminating and winding the positive electrode plate, the negative electrode plate and the separator;
Flat pressing means for flatly pressing the wound body formed by the winding means;
The electrode activity is performed before the winding means, and the portion of the positive electrode plate and the negative electrode plate that is a bent portion of the flat body formed by the flat press means is applied to one or both of the electrode plates. An inner peripheral surface side processing means for forming a groove-like groove-shaped portion along the short side direction on the inner peripheral surface side of the material layer, and a portion to be a bent portion of the flat body formed by the flat press means One or both processing means of the electrode active material layer and the outer peripheral surface side processing means for forming the cut portion or the groove-shaped portion cut along the short side direction on the outer peripheral surface side,
An apparatus for manufacturing a wound battery, comprising:   14. The wound battery manufacturing apparatus according to claim 13, further comprising processing scrap removing means for removing processing scrap generated in association with the formation of the groove portion or the cut portion.

Images