JP2017143005A - Power storage element and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage element which simplifies a configuration for suppressing generation of wrinkles in an electrode plate, and to provide a manufacturing method therefor.SOLUTION: In a power storage element 100 including an electrode body 20 formed of wound positive electrode plate 21 and negative electrode plate 22, the positive electrode plate 21 and negative electrode plate 22 have profile change parts 24, formed by salients extending in the winding direction, at the ends 21d and 22d of the positive electrode plate 21 and negative electrode plate 22 in the winding axis A direction in the bends of the positive electrode plate 21 and negative electrode plate 22.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a power storage device including an electrode body and a method for manufacturing the same.

  A power storage device such as a lithium ion secondary battery includes an electrode body formed by stacking a positive electrode plate, a negative electrode plate, a sheet-like separator inserted between the positive electrode plate and the negative electrode plate, and winding them in a spiral shape. There is something. For example, Patent Document 1 describes a lithium battery including an electrode plate as a wound electrode plate. In the electrode plate, an electrode material constituting an active material is applied to a current collector constituting the base material. The film thickness of the electrode material applied on the current collector is not constant but varies. This suppresses wrinkles and the like from being generated on the electrode plate when the electrode plate is wound. In addition, generation | occurrence | production of the wrinkle in an electrode plate may have a bad influence on the performance of a battery.

Special table 2012-501052 gazette

  In Patent Document 1, in order to suppress the generation of wrinkles in the electrode plate, the film thickness of the electrode material is changed according to the location on the electrode plate. For this reason, the manufacturing of the electrode plate is complicated and complicated. That is, the configuration for suppressing the generation of wrinkles on the electrode plate is complicated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power storage device that simplifies a configuration for suppressing generation of wrinkles and the like in an electrode plate.

  In order to achieve the above object, an electricity storage device according to the present invention is an electricity storage device including an electrode body formed by a wound electrode plate, and the electrode plate is a winding of the electrode plate in a curved portion of the electrode plate. It has a cross-sectional change part formed by the convex part or recessed part extended along the winding direction of an electrode plate in the edge part of a rotating shaft direction.

  In the above-described configuration, the cross-section changing portion that forms the convex portion or the concave portion extending along the winding direction suppresses the fold along the winding axis direction from entering the electrode plate. Therefore, the cross-section changing portion suppresses the folds, wrinkles, and the like of the electrode plate formed on the edge side of the end portion of the electrode plate from the cross-section changing portion in the winding axis direction from extending beyond the cross-section changing portion. Therefore, the occurrence of wrinkles, creases, and the like in the electrode plate is suppressed by a simple configuration using the cross-section changing portion that forms the convex portion or the concave portion.

  The cross-section changing portion may be formed by a deformed portion having a strip shape of an electrode plate. With the above-described configuration, the configuration of the cross-section changing portion is simplified. Further, the deformed portion may be formed by a bent portion of the electrode plate. With the above-described configuration, the configuration of the cross-section changing portion is further simplified.

  The electrode plate has a base material and an active material layer formed on the base material, and the cross-section change portion is located at a non-formation portion of the active material layer at an end portion in the winding axis direction of the base material. Also good. In the above structure, the interval between the adjacent active material layers can be made uniform by not forming the cross-section changing portion in the active material layer. Thereby, current bias in the active material layer is reduced.

  The cross-section changing portion may be disposed at least at the end of the outermost electrode plate of the winding among the end portions of the electrode plate. In the configuration described above, wrinkles, folds, etc. are generated at the end of the electrode plate by arranging the cross-section change part at the end of the outermost electrode plate that is most likely to contact and deform other than the electrode body. Is effectively suppressed.

  The power storage element is further provided with a separator that is wound together with the electrode plates and interposed between the electrode plates that are wound and overlapped, and the cross-sectional change portion includes an edge in the winding axis direction of the separator and a winding axis direction of the electrode plate. You may arrange | position between edges. In the above-described configuration, the cross-section changing portion is prevented from coming into contact with the separator and being damaged.

  The power storage element further includes a current collector that forms a gap and has a connection portion that is connected to the electrode body by sandwiching the electrode body in the gap, and the electrode body is narrow in a direction intersecting the winding axis. The end portion of the electrode plate that is inserted into the gap in response to the deformation and the cross-section changing portion is located may be located in the gap. In the above-described configuration, the cross-section changing portion suppresses the generation of wrinkles, folds, and the like in the electrode plate at the portion subjected to deformation in the electrode body.

  The method for manufacturing an electric storage element includes a step of winding an electrode plate to produce an electrode body, and a step of forming a cross-sectional change portion on the electrode plate when the electrode plate is wound or after the electrode plate is wound.

  According to the electricity storage device of the present invention, it is possible to simplify the configuration for suppressing the occurrence of wrinkles and the like on the electrode plate.

It is a perspective view which shows typically the external appearance of the electrical storage element which concerns on embodiment of this invention. It is a disassembled perspective view of the electrical storage element of FIG. FIG. 3 is a perspective view in which a part of the electrode body of FIG. 2 is developed. It is a side view of the electrode body which shows the state by which the curved wall-shaped part by the side of the positive electrode uncoated part in the electrode body of FIG. 3 was restrict | squeezed in the width direction. FIG. 5 is a side view showing a state where the electrode body of FIG. 4 is joined to a positive electrode current collector. FIG. 4 is an enlarged perspective view of the vicinity of a curved wall portion on the positive electrode uncoated portion side in the electrode body of FIG. 3. It is a perspective view which shows another example of the cross-section change part formed in the electrode body of FIG. It is a perspective view which shows the electrode body in the modification of the electrical storage element which concerns on embodiment similarly to FIG.

  Hereinafter, a power storage device according to an embodiment of the present invention will be described with reference to the drawings. It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

  Each figure in the accompanying drawings is a schematic diagram and is not necessarily illustrated strictly. Furthermore, in each figure, the same code | symbol is attached | subjected about the same or similar component. In the following description of the embodiments, expressions with “substantially” such as substantially parallel and substantially orthogonal may be used. For example, “substantially parallel” not only means completely parallel, but also means substantially parallel, that is, including a difference of, for example, several percent. The same applies to expressions involving other “abbreviations”.

[Embodiment]
The structure of the electrical storage element 100 which concerns on embodiment is demonstrated. FIG. 1 is a perspective view schematically showing an external appearance of a power storage device 100 according to the embodiment. As shown in FIG. 1, the power storage element 100 has a flat rectangular parallelepiped outer shape. The storage element 100 is a chargeable / dischargeable secondary battery. For example, the electricity storage element 100 is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery (also called a lithium battery). However, the storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery or a capacitor.

  Referring to FIGS. 1 and 2, the electric storage element 100 includes a flat rectangular parallelepiped container 10, an electrode body 20 included in the container 10, a positive electrode terminal 30, and a negative electrode terminal 40. The container 10 has a bottomed rectangular tube-shaped container body 11 and an elongated rectangular plate-like lid body 12 that can close the elongated rectangular opening 11 a of the container body 11. 2 is an exploded perspective view of the storage element 100 of FIG. The container body 11 has a flat rectangular parallelepiped outer shape. On the outer surface 12 a of the lid body 12, the positive terminal 30 and the negative terminal 40 are disposed. The container 10 is filled with an electrolyte such as an electrolytic solution (in this embodiment, a nonaqueous electrolytic solution) together with the electrode body 20, but the illustration of the electrolyte is omitted. As the electrolyte sealed in the container 10, there is no particular limitation on the type thereof as long as it does not impair the performance of the electricity storage device 100, and various types can be selected.

  The container body 11 and the lid body 12 are fixed with their joints in an airtight state by a joining method such as welding. Thereby, the container 10 forms the space sealed inside. Although it does not limit, the container main body 11 and the cover body 12 may be produced from weldable metals, such as stainless steel, aluminum, aluminum alloy, for example.

  The positive electrode terminal 30 and the negative electrode terminal 40 having conductivity extend through the lid body 12 to the opposite side to the outer surface 12a of the lid body 12, and on the opposite side, the positive electrode current collector 50 having conductivity and Connected to the negative electrode current collector 60. The positive electrode current collector 50 and the negative electrode current collector 60 are further connected to the electrode body 20.

  An upper insulating member 31 is provided between the positive electrode terminal 30 and the lid body 12 to electrically insulate them from each other, and a lower insulating member 32 is provided between the lid body 12 and the positive electrode current collector 50. These are electrically insulated from each other. An upper insulating member 41 is provided between the negative electrode terminal 40 and the lid body 12 to electrically insulate them from each other, and a lower insulating member 42 is provided between the lid body 12 and the negative electrode current collector 60. These are electrically insulated from each other. The insulating members 31, 32, 41, and 42 are all formed from a material having electrical insulation properties such as resin, and constitute, for example, a packing, a gasket, and the like. The electrode body 20 is provided so as to be suspended from the lid body 12 via the positive electrode current collector 50 and the negative electrode current collector 60. The electrode body 20 is housed in the container body 11 together with the positive electrode current collector 50 and the negative electrode current collector 60. In order to electrically insulate between the electrode body 20 and the container body 11, the electrode body 20 may be covered with an insulating film or the like. A buffer material such as a spacer may be provided between the electrode body 20 and the container body 11.

  With reference to FIG.2 and FIG.3, the structure of the electrode body 20 is demonstrated. FIG. 3 is a perspective view in which a part of the electrode body 20 of FIG. 2 is developed. The electrode body 20 is a power generation element capable of storing electricity. The electrode body 20 includes a sheet-like positive electrode plate 21 having a long rectangular belt-like planar shape, a sheet-like negative electrode plate 22 having a long rectangular belt-like planar shape, and a long rectangular belt-like planar shape. The sheet-like two separators 23 are included so as to be layered. Here, the positive electrode plate 21 and the negative electrode plate 22 are examples of electrode plates.

  Then, the electrode body 20 is wound in a spiral manner in the winding direction B around the winding axis A together with the positive electrode plate 21, the negative electrode plate 22 and the separator 23 stacked in layers, It is formed. The winding axis A is a virtual axis indicated by a one-dot chain line in FIGS. 2 and 3, and the electrode body 20 has a substantially symmetric configuration with respect to the winding axis A. Although not limited, in the present embodiment, the electrode body 20 has a flat outer shape having an oblong shape with a flat cross section perpendicular to the winding axis A. However, the cross-sectional shape of the electrode body 20 may be other than an oval shape, and may be a circle, an ellipse, a rectangle, or other polygons.

  The positive electrode plate 21 includes a positive electrode base material 21a which is a long rectangular strip-shaped metal foil made of a metal such as aluminum or an aluminum alloy, and a coating or the like substantially over the wide main surface on both sides of the positive electrode base material 21a. And a positive electrode active material layer 21b (indicated by hatching in FIG. 3) stacked by the method. The negative electrode plate 22 includes a negative electrode base material 22a which is a long rectangular belt-shaped metal foil made of a metal such as copper or a copper alloy, and a coating or the like substantially over the wide main surface on both sides of the negative electrode base material 22a. And a negative electrode active material layer 22b (indicated by hatching in FIG. 3) stacked by the method. As a positive electrode active material used for the positive electrode active material layer 21b or a negative electrode active material used for the negative electrode active material layer 22b, a known material is appropriately used as long as it is a positive electrode active material or a negative electrode active material capable of occluding and releasing lithium ions. it can. The separator 23 is a microporous sheet made of a material having electrical insulation properties such as a resin. In the present embodiment, the positive electrode active material layer 21b and the negative electrode active material layer 22b are formed on the main surfaces on both sides of the positive electrode substrate 21a and the negative electrode substrate 22a, respectively, but only on one main surface. May be formed. Here, the positive electrode base material 21a and the negative electrode base material 22a are examples of the electrode plate base material, and the positive electrode active material layer 21b and the negative electrode active material layer 22b are examples of the electrode plate active material layer.

  In the band-like region in the vicinity of one of the two edges along the longitudinal direction of the positive electrode plate 21, the positive electrode active material layer 21b is not laminated on any main surface of the positive electrode base material 21a. The edge portion of the positive electrode plate 21 that forms the band-like region is referred to as a positive electrode uncoated portion 21c. That is, the positive electrode plate 21 has a positive electrode uncoated portion 21 c at one end portion 21 d of two ends in the winding axis A direction that is a direction along the winding axis A. The positive electrode uncoated portion 21 c is formed by the exposed positive electrode base material 21 a and forms a current collecting region of the positive electrode plate 21.

  Furthermore, the negative electrode active material layer 22b is not laminated on any main surface of the negative electrode substrate 22a in the band-like region in the vicinity of one of the two edges along the longitudinal direction of the negative electrode plate 22. The edge portion of the negative electrode plate 22 that forms the belt-like region is referred to as a negative electrode uncoated portion 22c. That is, the negative electrode plate 22 has a negative electrode uncoated portion 22c at one end 22d of two ends in the winding axis A direction. The negative electrode uncoated portion 22 c is formed by the exposed negative electrode base material 22 a and forms a current collecting region of the negative electrode plate 22. Here, the end portions 21d and 22d are examples of end portions of the electrode plate, and the positive electrode uncoated portion 21c and the negative electrode uncoated portion 22c are examples of non-forming portions of the active material layer.

  The positive electrode plate 21 and the negative electrode plate 22 are overlapped with each other in the same longitudinal direction for winding. At this time, the positive electrode uncoated portion 21c and the negative electrode uncoated portion 22c are positioned on opposite sides of the overlapping portion of the positive electrode plate 21 and the negative electrode plate 22. In the winding axis A direction, the edge 21ca of the positive electrode uncoated portion 21c protrudes beyond the edge of the negative electrode plate 22 located on the same side of the overlapping portion as the edge 21ca. The edge 22ca of the negative electrode uncoated portion 22c protrudes from the edge of the positive electrode plate 21 located on the same side of the overlapping portion with the edge 22ca. Here, the edges 21ca and 22ca are examples of edges of the electrode plate.

  Two separators 23 are respectively provided on flat main surfaces on both sides of one negative electrode plate 22. At this time, the entire negative electrode plate 22 except the negative electrode uncoated portion 22 c is covered with the separator 23. Then, the negative electrode uncoated portion 22 c protrudes from the separator 23 through between the two separators 23. Furthermore, one positive electrode plate 21 is provided on the separator 23 so as to be positioned further inside the separator 23 adjacent to the negative electrode plate 22 on the inner side during winding. At this time, the entire positive electrode plate 21 excluding the positive electrode uncoated portion 21 c is covered with the negative electrode plate 22 and the separator 23 and faces the negative electrode plate 22. The positive electrode uncoated portion 21 c protrudes beyond the two separators 23.

  In the state where one positive electrode plate 21, one negative electrode plate 22, and two separators 23 laminated as described above are overlapped, the positive electrode plate 21 is wound in a spiral shape in the winding direction B around the winding axis A. Thereby, the electrode body 20 is formed. In the electrode body 20 after winding, the edges 21ca of the stacked positive electrode uncoated portions 21c are arranged in a planar shape to form an end portion 20a of the electrode body 20. Further, the edges 22ca of the laminated negative electrode uncoated portions 22c are arranged in a planar shape to form the end portion 20b of the electrode body 20. The ends 20a and 20b extend substantially perpendicular to the winding axis A.

  Further, in the electrode body 20 after winding, the stacked positive electrode plate 21, negative electrode plate 22 and separator 23 form a wall-like body extending along the winding direction B. Specifically, the wall-like body is positioned opposite to the two flat wall-shaped portions 20c and 20d that are wide and flat while being opposed to each other with the winding axis A interposed therebetween. And two curved wall portions 20e and 20f that are curved in a semicircular shape. The flat wall portions 20c and 20d extend substantially parallel to each other. The curved wall portions 20e and 20f respectively connect the flat wall portion 20c and the flat wall portion 20d to each other at both ends.

  2 to 4, at the end 20a of the electrode body 20, a plurality of positive electrode uncoated portions 21c of the flat wall-shaped portion 20c and a plurality of positive electrode uncoated portions 21c of the flat wall-shaped portion 20d are formed. Are divided in a direction substantially perpendicular to the extending direction of the flat wall portions 20c and 20d. Furthermore, the positive electrode uncoated portion 21c divided into two parts is focused. The converged positive electrode uncoated portion 21 c is connected to the positive electrode current collector 50. 4 is a side view of the electrode body 20 showing a state in which the curved wall-shaped portion 20e on the positive electrode uncoated portion 21c side in the electrode body 20 of FIG. 3 is narrowed in the width direction. It is the side view seen from the part 20a side. The width of the curved wall portion 20e is a width in a direction from the flat wall portion 20c toward the flat wall portion 20d.

  The positive electrode current collector 50 integrally includes one plate-like first fixing portion 50a and two leg-like second fixing portions 50b, and is similar to the positive electrode substrate 21a of the positive electrode plate 21 of the electrode body 20. Can be formed from the following materials: The first fixing portion 50a is connected to the shaft portion 30a of the positive terminal 30 extending through the lid body 12 by various connection methods such as caulking and welding. The two second fixing portions 50b are respectively connected to the positive electrode uncoated portion 21c focused by the flat wall portions 20c and 20d. The second fixing portion 50b is sandwiched between the positive electrode uncoated portions 21c converged together with the contact plate 51, and is joined to the contact plate 51 by welding such as ultrasonic welding or resistance welding. Thereby, the 2nd fixing | fixed part 50b, the contact plate 51, and the positive electrode uncoated part 21c are joined together. The backing plate 51 may be a clip that sandwiches the second fixed portion 50b and the positive electrode uncoated portion 21c from both sides. Here, the 2nd fixing | fixed part 50b is an example of the connection part of a collector.

  Similarly, at the end portion 20b of the electrode body 20, a plurality of negative electrode uncoated portions 22c of the flat wall-shaped portion 20c and a plurality of negative electrode uncoated portions 22c of the flat wall-shaped portion 20d are flat wall-shaped. The portions 20c and 20d are focused in a direction substantially perpendicular to the extending direction of the portions 20c and 20d. The converged negative electrode uncoated portion 22 c is connected to the negative electrode current collector 60.

  The negative electrode current collector 60 has one plate-like first fixing part 60a and two leg-like second fixing parts 60b, and is the same as the negative electrode substrate 22a of the negative electrode plate 22 of the electrode body 20. Can be formed from the following materials: The first fixing portion 60a is connected to the shaft portion 40a of the negative electrode terminal 40 extending through the lid body 12 by various connection methods such as caulking and welding. The two second fixing portions 60b are respectively connected to the negative electrode uncoated portion 22c focused by the flat wall portions 20c and 20d. The second fixing portion 60b sandwiches the negative electrode uncoated portion 22c converged together with the contact plate 61, and is joined to the contact plate 61 by welding. Thereby, the 2nd fixing | fixed part 60b, the contact plate 61, and the negative electrode uncoated part 22c are joined together. The backing plate 61 may be a clip that sandwiches the second fixed portion 60b and the negative electrode uncoated portion 22c from both sides. Here, the 2nd fixing | fixed part 60b is an example of the connection part of an electrical power collector.

  As described above, the electrode body 20 electrically and physically connected to the positive electrode terminal 30 and the negative electrode terminal 40 through the positive electrode current collector 50 and the negative electrode current collector 60 respectively has its winding axis A as a lid body. 12 is fixed to the lid 12 in a direction along the direction 12. The electrode body 20 as described above is called a vertically wound electrode body.

  Referring to FIGS. 3 and 5, in the positive electrode current collector 50, the two second fixing portions 50 b are located at positions facing each other across the first fixing portion 50 a and are in the same direction from the first fixing portion 50 a. It protrudes. FIG. 5 is a side view showing a state where the electrode body 20 of FIG. 4 is joined to the positive electrode current collector 50. Furthermore, although not limited to this, in the present embodiment, the two second fixing portions 50b extend substantially parallel to each other. The width B1 of the gap G between the two second fixed portions 50b is smaller than the width B2 of the electrode body 20 in the direction from the flat wall portion 20c toward the flat wall portion 20d. Further, the two second fixing portions 50b are located on the center side of the electrode body 20, that is, on the winding axis A side, from the outer surfaces of the flat wall portions 20c and 20d.

  In the electrode body 20, the positive electrode uncoated portion 21 c extending from the curved wall portion 20 e to a part of the flat wall portions 20 c and 20 d is positioned in the gap G between the two second fixed portions 50 b of the positive electrode current collector 50. It is made to pinch from the outside by the 2nd fixing | fixed part 50b, and is joined with the 2nd fixing | fixed part 50b.

  For this reason, as shown in FIGS. 4 to 6, the width of the positive electrode uncoated portion 21 c extends from the curved wall portion 20 e located in the gap G to the flat wall portions 20 c and 20 d within the width B 1 of the gap G. It is narrowed to fit in. FIG. 6 is an enlarged perspective view of the vicinity of the curved wall-shaped portion 20e on the positive electrode uncoated portion 21c side in the electrode body 20 of FIG. Then, in order to narrow the width of the positive electrode uncoated portion 21c of the curved wall-shaped portion 20e, that is, the curved positive electrode uncoated portion 21ce, the positive electrode uncoated portion 21c is flat at or near the curved positive electrode uncoated portion 21ce. It is pressed toward the center of the electrode body 20 which is the inside of the flat wall-shaped portions 20c and 20d from the outside of the wall-shaped portion 20c and the flat wall-shaped portion 20d. The pressing position P can reduce the overall width of the curved positive electrode uncoated portion 21ce that is deformed by pressing so that the diameter thereof is reduced, but the curved shape is smooth and the stacking state such as the stacking interval is greatly increased. It is desirable that the position is such that it can be prevented from collapsing and can be prevented from expanding so as to return the width after releasing the pressure.

  When a pressing force in a direction substantially perpendicular to the flat wall portions 20c and 20d acts on the position P, the position P is in a direction substantially perpendicular to the flat wall portions 20c and 20d, as shown in FIG. A position facing the innermost circumferential surface 21ceb of the curved positive electrode uncoated portion 21ce or a position in the vicinity thereof is desirable. The innermost peripheral surface 21ceb is the inner peripheral surface of the positive electrode base material 21a that constitutes the curved positive electrode uncoated portion 21ce located on the innermost side in the plurality of layers of the curved positive electrode uncoated portion 21ce. Further, the position P is a direction substantially perpendicular to the flat wall-shaped portions 20c and 20d and is opposed to the innermost peripheral surface 21ceb of the curved positive electrode uncoated portion 21ce, or a flat wall shape near the innermost peripheral surface 21ceb. It is more desirable that the position is opposite to the innermost peripheral surface of the positive electrode uncoated portion 21c in the portions 20c and 20d. Furthermore, the position P is more preferably a position facing the innermost peripheral surface 21ceb in a direction substantially perpendicular to the flat wall portions 20c and 20d.

  For example, the position P is opposite to the flat wall-shaped portions 20c and 20d, that is, the curved positive electrode is not positioned with respect to the position facing the innermost peripheral surface 21ceb in the direction substantially perpendicular to the flat wall-shaped portions 20c and 20d or the vicinity thereof. When located on the protruding side of the coating part 21ce, the curved positive electrode uncoated part 21ce is partially deformed so that only the position P and its vicinity are recessed toward the inside in the radial direction. As a result, there is a high possibility that the desired width of the curved positive electrode uncoated portion 21ce cannot be obtained. Further, when the position P is located on the side of the flat wall portions 20c and 20d, away from the position facing the innermost peripheral surface 21ceb or in the vicinity thereof in the direction substantially perpendicular to the flat wall portions 20c and 20d, The electrode body 20 whose width is narrowed by receiving pressure behaves such that the width is restored after the pressing force is released.

  By receiving the pressure at the position P as described above, the positive electrode uncoated portion 21c is entirely reduced in width at a portion corresponding to the gap G of the second fixed portion 50b of the positive electrode current collector 50, and the curved positive electrode A shape that is narrowed so as to further narrow the width is formed at or near the uncoated portion 21ce. The negative electrode uncoated portion 22c is also configured to be pressed in the same manner as the positive electrode uncoated portion 21c. The negative electrode uncoated portion 22c is narrowed as a whole at a portion corresponding to the gap G of the second fixed portion 60b of the negative electrode current collector 60 having the same configuration as the positive electrode current collector 50, and the curved negative electrode A shape that is narrowed to further narrow the width is formed at or near the uncoated portion 22ce.

  When the curved positive electrode uncoated portion 21ce and the curved negative electrode uncoated portion 22ce are deformed as described above, folds, wrinkles, and the like may occur in the positive electrode uncoated portion 21c and the negative electrode uncoated portion 22c. Further, when the flat wall-like portions 20c and 20d of the electrode body 20 are focused, the positive electrode uncoated portion 21c and the negative electrode uncoated portion 22c centered on the curved positive electrode uncoated portion 21ce and the curved negative electrode uncoated portion 22ce In some cases, creases, wrinkles, etc. may occur.

  When the curved positive electrode uncoated portion 21ce in a state including a crease, a crease or the like is subjected to the above-described deformation or an external force, the crease, the crease or the like grows and extends in the winding axis A direction of the electrode body 20, There is a possibility that the positive electrode plate 21 may reach a portion where the positive electrode active material layer 21 b is formed or a portion facing the separator 23. Similarly, when the curved negative electrode uncoated portion 22ce including folds, wrinkles, etc. is subjected to the above-described deformation or external force, the folds, wrinkles, etc. grow in the direction of the winding axis A of the electrode body 20. May extend to the formation site of the negative electrode active material layer 22 b in the negative electrode plate 22 or the site facing the separator 23. In a portion including a fold, a crease or the like in the positive electrode active material layer 21b and the negative electrode active material layer 22b, the distance between the adjacent negative electrode plate 22 and the positive electrode plate 21 becomes non-uniform, and current bias may occur. Further, if the grown folds, wrinkles, etc. have a shape that protrudes sharply, the separator 23 may be pierced, thereby causing a short circuit between the positive electrode plate 21 and the negative electrode plate 22.

  In order to suppress the expansion of folds, wrinkles and the like in the winding axis A direction, the curved positive electrode uncoated portion 21ce of the electrode body 20 is curved in the winding direction B of the electrode body 20, as shown in FIG. A cross-section changing portion 24 having a belt-like protrusion shape extending along the circumferential direction of the positive electrode uncoated portion 21ce is formed. That is, the cross-section changing part 24 extends in a direction intersecting with the extending direction of folds, wrinkles and the like. Further, the cross-section changing portion 24 is formed on the curved positive electrode uncoated portion 21ce, the edge 23a proximal to the positive electrode uncoated portion 21c in the separator 23, and the positive electrode uncoated which is the edge of the curved positive electrode uncoated portion 21ce. It is located between the edge 21ca of the part 21c. And the cross-section change part 24 is formed before the said deformation | transformation of the curved positive electrode uncoated part 21ce. Here, the cross-section changing portion 24 is an example of a cross-section changing portion formed by a convex portion.

  In the present embodiment, the cross-section changing portion 24 deforms the positive electrode uncoated portion 21c to form a convex portion that protrudes from the inside of the electrode body 20 to the outside, that is, radially outward. It is comprised by the crease | fold or crease | fold formed in this. The cross-section changing portion 24 may be formed by folding the positive electrode uncoated portion 21 c along the winding direction B. That is, the cross-section changing portion 24 improves the rigidity of the curved positive electrode uncoated portion 21ce with respect to bending stress around the winding axis A that forms a fold along the winding axis A direction in the curved positive electrode uncoated portion 21ce. Formed as follows. Such a cross-section changing portion 24 suppresses the creases, wrinkles, etc. generated in the curved positive electrode uncoated portion 21ce from extending beyond the cross-section changing portion 24 in the winding axis A direction toward the edge 23a of the separator 23. To do.

  In the present embodiment, the cross-section changing portion 24 is formed only in the outermost curved positive electrode uncoated portion 21cea located on the outermost periphery of the multiple layers of curved positive electrode uncoated portions 21ce. However, the cross-section changing portion 24 may be formed in a plurality of layers of the curved positive electrode uncoated portion 21ce in the radial direction from the outermost curved positive electrode uncoated portion 21cea, and the outermost curved positive electrode uncoated portion 21cea. It may be formed in one or more layers of the curved positive electrode uncoated portion 21ce, or may be formed in all layers of the curved positive electrode uncoated portion 21ce.

  Further, in the present embodiment, the cross-section changing portion 24 includes the most protruding portion in the curved positive electrode uncoated portion 21ce in the direction along the flat wall portions 20c and 20d, that is, the portion farthest from the winding axis A. And extends over a portion of the curved positive electrode uncoated portion 21ce along the winding direction B. The most protruding portion of the curved positive electrode uncoated portion 21ce is a portion where the largest bending moment acts when the positive electrode uncoated portion 21c is pressed at the position P. That is, it is desirable that the cross-section changing portion 24 is arranged so as to include a portion where the largest bending moment acts as described above.

  In addition, it is desirable that the cross-section changing portion 24 be disposed on the opposite side of the curved positive electrode uncoated portion 21ce with respect to the position P from the flat wall portions 20c and 20d. Furthermore, it is desirable that the cross-section changing portion 24 is away from the position P. The cross-section changing portion 24 away from the position P can fulfill the function of suppressing the expansion of wrinkles, creases, etc. without being crushed when pressed. The cross-section changing portion 24 arranged on the opposite side of the flat wall-shaped portions 20c and 20d with respect to the position P effectively suppresses the expansion of wrinkles, creases, etc. at the portions that are largely deformed when pressed in the curved positive electrode uncoated portion 21ce. To do.

  In addition, it is desirable that the cross-section changing portion 24 is disposed closer to the positive electrode active material layer 21b side than the edge side of the curved positive electrode uncoated portion 21ce in the winding axis A direction. This is because the deformation amount of the curved positive electrode uncoated portion 21ce on the positive electrode active material layer 21b side is smaller than the edge side of the curved positive electrode uncoated portion 21ce.

  Moreover, in this Embodiment, the cross-sectional change part 24 is extended along the winding direction B of the electrode body 20, ie, along the edge 21ca of the positive electrode uncoated part 21c, and the edge 23a of the separator 23. It is extended. The cross-section changing portion 24 may extend in a direction that simply intersects with the winding axis A of the electrode body 20.

  In the curved negative electrode uncoated portion 22ce of the electrode body 20, similarly to the curved negative electrode uncoated portion 21ce, a belt-like protrusion-shaped cross-section changing portion 24 extending along the circumferential direction of the curved negative electrode uncoated portion 22ce is provided. Is formed. On the negative electrode plate 22, the cross-section changing part 24 is located between the edge 23b of the separator 23 opposite to the edge 23a and the edge 22ca of the negative electrode uncoated part 22c.

  In the present embodiment, one cross-section changing portion 24 is disposed in each of the curved positive electrode uncoated portion 21ce and the curved negative electrode uncoated portion 22ce in the winding axis A direction of the electrode body 20. Furthermore, in the winding direction B of the electrode body 20, one cross-section changing portion 24 is disposed in each of the curved positive electrode uncoated portion 21ce and the curved negative electrode uncoated portion 22ce. Two or more cross-section changing portions 24 may be arranged in any of the winding axis A direction and the winding direction B.

  Further, the cross-section changing portion 24 may extend over the entire curved positive electrode uncoated portion 21ce in the winding direction B of the electrode body 20, and in this case, the cross-section changing portion 24 is discontinuous even if continuous. It may be. Further, as shown in FIG. 7, the cross-section changing portion 24 may extend over the entire curved positive electrode uncoated portion 21ce and to at least one positive electrode uncoated portion 21c of the flat wall portions 20c and 20d. The cross-section changing portion 24 formed in the curved negative electrode uncoated portion 22ce may also have the same configuration as that of the cross-section changing portion 24 of the curved positive electrode uncoated portion 21ce.

  Moreover, in this Embodiment, the cross-sectional change part 24 is each in the positive electrode uncoated part 21c and the negative electrode uncoated part 22c of the positive electrode plate 21 and the negative electrode plate 22 which are pulled out from a roll at the time of winding of the electrode body 20. May be formed.

  As described above, the energy storage device 100 according to the present embodiment includes the electrode body 20 formed by the positive electrode plate 21 and the negative electrode plate 22 that are wound. The positive electrode plate 21 and the negative electrode plate 22 are wound around the end portions 21 d and 22 d in the winding axis A direction of the positive electrode plate 21 and the negative electrode plate 22 in the curved portions of the positive electrode plate 21 and the negative electrode plate 22. The cross-section changing portion 24 is formed by a convex portion extending along the turning direction B.

  In the above-described configuration, the cross-section changing portion 24 that forms the convex portion extending along the winding direction B suppresses the folds along the winding axis A direction from entering the positive electrode plate 21 and the negative electrode plate 22. Therefore, the cross-section changing portion 24 is in the winding axis A direction, and the cross-section changing portion 24 has a fold, a crease, and the like of the positive electrode plate 21 formed on the edge 21ca side of the end 21d of the positive electrode plate 21 with respect to the cross-section changing portion 24. In addition, the folds, wrinkles, and the like of the negative electrode plate 22 formed on the edge 22ca side of the end 22d of the negative electrode plate 22 are prevented from extending beyond the cross-section changing portion 24 to the opposite side. Therefore, the occurrence of wrinkles, creases, and the like in the positive electrode plate 21 and the negative electrode plate 22 is suppressed by a simple configuration using the cross-sectional change portion 24 that forms the convex portion.

  In power storage element 100 according to the embodiment, cross-section changing portion 24 is formed by a belt-like deformed portion of positive electrode plate 21 and negative electrode plate 22. Further, the cross-section changing portion 24 formed by the deformed portion is formed by a bent portion of the positive electrode plate 21 and the negative electrode plate 22. With the above-described configuration, the configuration of the cross-section changing unit 24 is simplified.

  In the electricity storage device 100 according to the embodiment, the positive electrode plate 21 and the negative electrode plate 22 are respectively a positive electrode base material 21a and a negative electrode base material 22a, and a positive electrode active material layer 21b formed on the positive electrode base material 21a and the negative electrode base material 22a. And a negative electrode active material layer 22b. The cross-section changing portion 24 includes a positive electrode uncoated portion 21c that is a non-forming portion of the positive electrode active material layer 21b at the end portion 21d in the winding axis A direction of the positive electrode base material 21a, and a winding axis A of the negative electrode base material 22a. It is located in the negative electrode uncoated portion 22c which is a non-formation portion of the negative electrode active material layer 22b at the end 22d in the direction. In the above-described configuration, since the cross-sectional change portion 24 is not formed in the positive electrode active material layer 21b and the negative electrode active material layer 22b, the interval between the positive electrode active material layer 21b and the negative electrode active material layer 22b stacked adjacent to each other can be made uniform. it can. Thereby, current bias in the positive electrode active material layer 21b and the negative electrode active material layer 22b is reduced.

  In the electricity storage device 100 according to the embodiment, the cross-section changing portion 24 is disposed at least at the end portion 21 d of the positive electrode plate 21 at the outermost periphery of the winding among the end portions 21 d of the positive electrode plate 21. Further, the cross-section changing portion 24 is disposed at least at the end portion 22d of the negative electrode plate 22 at the outermost periphery of the winding in the end portion 22d of the negative electrode plate 22. In the above-described configuration, the positive electrode plate is provided by disposing the cross-section changing portions 24 at the end portions 21d and 22d of the outermost positive electrode plate 21 and the negative electrode plate 22 that are most likely to come into contact with the electrode body 20 and deform. Occurrence of wrinkles, creases, etc. at the end 21d of 21 and the end 22d of the negative electrode plate 22 is effectively suppressed.

  The power storage device 100 according to the embodiment includes a separator 23 that is wound together with the positive electrode plate 21 and the negative electrode plate 22 and interposed between the positive electrode plate 21 and the negative electrode plate 22 that are wound and overlapped. The cross-section changing portion 24 is disposed between the edge 23a or 23b of the separator 23 in the winding axis A direction and the edge 21ca of the positive electrode plate 21 in the winding axis A direction or the edge 22ca of the negative electrode plate 22 in the winding axis A direction. Is done. In the above-described configuration, the cross-section changing portion 24 is prevented from coming into contact with the separator 23 and being damaged.

  The power storage device 100 according to the embodiment includes a positive electrode current collector 50 having second fixing portions 50b and 60b that form a gap G and sandwich the electrode body 20 in the gap G and are connected to the electrode body 20. A negative electrode current collector 60 is provided. The electrode body 20 is inserted into the gap G under deformation that becomes narrow in the direction crossing the winding axis A, and the positive electrode plate 21 where the cross-section changing portion 24 is located and the end portion 21d of the negative electrode plate 22 and 22d is located in the gap G. In the above-described configuration, the cross-section changing portion 24 suppresses the generation of wrinkles, creases, and the like in the positive electrode plate 21 and the negative electrode plate 22 at the portions that are subject to deformation in the electrode body 20.

  When manufacturing the electricity storage device 100 according to the embodiment, the manufacturing method includes the steps of winding the positive electrode plate 21 and the negative electrode plate 22 to produce the electrode body 20, and winding the positive electrode plate 21 and the negative electrode plate 22. Forming the cross-section changing portion 24 in the positive electrode plate 21 and the negative electrode plate 22. With the above-described configuration, the cross-section changing portion 24 can be efficiently formed at an arbitrary position on the positive electrode plate 21 and the negative electrode plate 22.

[Modification]
Moreover, the following structures are mentioned as a modification of the electrical storage element 100 which concerns on embodiment. Specifically, as illustrated in FIG. 8, in the electrode body 20 of the electricity storage device according to the modification, a groove-shaped cross-section changing portion 25 is formed instead of the belt-like protrusion-shaped cross-section changing portion 24. FIG. 8 is a perspective view showing the electrode body 20 in a modification of the energy storage device according to the embodiment in the same manner as FIG. Further, in the following description of the modified examples, the constituent elements having the same reference numerals as the reference numerals in the previous drawings are the same or similar constituent elements, and thus detailed description thereof is omitted.

  In the curved positive electrode uncoated portion 21ce of the positive electrode plate 21 of the electrode body 20, the cross-section changing portion 25 extending along the winding direction B of the electrode body 20 and recessed in a groove shape is a power storage device according to the embodiment. Although it is formed with the same position, shape and dimensions as the cross-section changing portion 24 in 100, it is not limited to this. In this modification, the cross-section changing portion 25 is a concave portion that is recessed in the curved positive electrode uncoated portion 21ce from the outside of the electrode body 20 toward the inside, that is, inward in the radial direction of the curved positive electrode uncoated portion 21ce. It is comprised by the fold formed so that it may form. The cross-section changing portion 25 may be formed by folding the positive electrode uncoated portion 21 c along the winding direction B so as to protrude inward of the electrode body 20. The cross-section changing portion 25 improves the rigidity of the curved positive electrode uncoated portion 21ce with respect to bending stress around the winding axis A so as to form a fold along the winding axis A direction in the curved positive electrode uncoated portion 21ce. It is formed. Such a cross-sectional change part 25 suppresses that the crease | fold, wrinkle, etc. which arose in the curved positive electrode uncoated part 21ce extend beyond the cross-section change part 25 in the winding axis A direction. Here, the cross-section changing portion 25 is an example of a cross-section changing portion formed by a recess.

  In the present modification, the cross-section changing portion 25 is formed only in the outermost curved positive electrode uncoated portion 21cea among the multiple layers of curved positive electrode uncoated portions 21ce. However, the cross-section changing portion 25 may be formed in the plurality of layers of the curved positive electrode uncoated portion 21ce in the radial direction from the outermost curved positive electrode uncoated portion 21cea, and the outermost curved positive electrode uncoated portion 21cea. It may be formed in one or more layers of the curved positive electrode uncoated portion 21ce, or may be formed in all layers of the curved positive electrode uncoated portion 21ce.

  It is desirable that the cross-section changing portion 25 is also arranged to include a portion where the largest bending moment acts when the positive electrode uncoated portion 21c of the electrode body 20 is pressed at the position P. And it is desirable for the cross-sectional change part 25 to be arrange | positioned regarding the position P in the curved positive electrode uncoated part 21ce on the opposite side to the flat wall-shaped parts 20c and 20d, and to be further away from the position P. It is desirable that the cross-section changing portion 25 is also disposed closer to the positive electrode active material layer 21b side than the edge side of the curved positive electrode uncoated portion 21ce in the winding axis A direction. It is desirable that the cross-section changing portion 25 is also disposed between the edge 21ca of the positive electrode uncoated portion 21c and the edge 23a of the separator 23. Although the cross-section changing portion 25 extends along the edge 21ca of the positive electrode uncoated portion 21c and the edge 23a of the separator 23, the cross-section changing portion 25 may extend in a direction that simply intersects with the winding axis A of the electrode body 20. Good.

  Also in the curved negative electrode uncoated portion 22ce of the electrode body 20, the groove-shaped cross-section changing portion 25 extending along the circumferential direction of the curved negative electrode uncoated portion 22ce is formed, similarly to the curved positive electrode uncoated portion 21ce. Has been.

  One cross-section changing portion 25 may be arranged in each of the curved positive electrode uncoated portion 21ce and the curved negative electrode uncoated portion 22ce, or two or more cross-section changing portions 25 may be arranged. The cross-section changing portion 25 may extend continuously or discontinuously over part or all of the curved positive electrode uncoated portion 21ce and the curved negative electrode uncoated portion 22ce in the winding direction B of the electrode body 20. Furthermore, it may extend over at least one of the flat wall portions 20c and 20d.

  The cross-section changing portion 25 of the present modification can be formed on each of the positive electrode uncoated portion 21c and the negative electrode uncoated portion 22c of the positive electrode plate 21 and the negative electrode plate 22 drawn from the roll when the electrode body 20 is wound. Alternatively, the cross-section changing portion 25 presses the positive electrode uncoated portion 21c and the negative electrode uncoated portion 22c linearly from the outside of the electrode body 20 toward the inside thereof in the wound electrode body 20. Can be formed. At this time, the cross-sectional change part 25 can be formed over the positive electrode uncoated part 21c or the negative electrode uncoated part 22c of multiple layers by one press. For example, when the cross-section changing portion 25 is formed in the wound electrode body 20, the cross-section changing portion is simultaneously with the time when the positive electrode uncoated portion 21c and the negative electrode uncoated portion 22c of the electrode body 20 are pressed at the position P. 25 may be formed. In this case, the jig that presses the positive electrode uncoated portion 21c or the negative electrode uncoated portion 22c at the two positions P covers and presses the curved positive electrode uncoated portion 21ce or the curved negative electrode uncoated portion 22ce. The protrusion which comprises and forms the cross-sectional change part 25 may be formed in the part of the jig | tool which is comprised and presses the curved negative electrode uncoated part 21ce or the curved negative electrode uncoated part 22ce.

  Other configurations of the power storage element according to the modification are the same as those of the power storage element 100 according to the embodiment, and thus the description thereof is omitted. Furthermore, according to the power storage device according to the modification, the same effect as that of power storage device 100 according to the embodiment can be obtained.

  Moreover, when manufacturing the electrical storage element which concerns on a modification, the manufacturing method is the process of winding the positive electrode plate 21 and the negative electrode plate 22, and producing the electrode body 20, the winding of the positive electrode plate 21 and the negative electrode plate 22, or Forming a cross-section changing portion 25 on the positive electrode plate 21 and the negative electrode plate 22 after winding. In the above-described configuration, the cross-section changing portion 25 can be efficiently formed at an arbitrary position of the positive electrode plate 21 and the negative electrode plate 22 when it is formed when the positive electrode plate 21 and the negative electrode plate 22 are wound. In addition, when the cross-section changing portion 25 is formed after the positive electrode plate 21 and the negative electrode plate 22 are wound, for example, the cross-section changing portion 25 can be formed by pressing the outer surface of the electrode body 20 after the winding. Therefore, the cross-section changing portion 25 can be formed by simple means.

[Other variations]
The power storage device according to the embodiment and the modification of the present invention has been described above, but the present invention is not limited to the embodiment and the modification. That is, it should be considered that the embodiment and the modification disclosed this time are examples in all respects and are not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  In the electrode body 20 of the energy storage device according to the embodiment and the modification, the cross-section changing portion 24 protrudes from the inside of the electrode body 20 to the outside, but from the outside of the electrode body 20 to the inside. May protrude. In addition, the cross-section changing portion 25 is recessed from the outside of the electrode body 20 toward the inside, but may be recessed from the inside of the electrode body 20 toward the outside.

  In the electrode body 20 of the energy storage device 100 according to the embodiment, the cross-section changing portion 24 is formed by bending the positive electrode base material 21a and the negative electrode base material 22a, but is not limited thereto. The cross-section changing portion 24 may be formed by bending the positive electrode base material 21a and the negative electrode base material 22a, or may be formed by a protrusion or a protruding portion integrally formed with the positive electrode base material 21a and the negative electrode base material 22a. You may form by the separate member affixed on the positive electrode base material 21a and the negative electrode base material 22a.

  In the electrode body 20 of the electricity storage device according to the modification, the cross-section changing portion 25 is formed by bending the positive electrode base material 21a and the negative electrode base material 22a, but is not limited thereto. The cross-section changing portion 25 may be formed by bending the positive electrode base material 21a and the negative electrode base material 22a, or may be formed as a part of each of the positive electrode base material 21a and the negative electrode base material 22a by integral molding. .

  In the electrode body 20 of the energy storage device according to the embodiment and the modification, the cross-section changing portions 24 and 25 are provided between the second fixing portion 50b of the positive electrode current collector 50 and the second fixing portion 60b of the negative electrode current collector 60. Although it was formed in the curved wall-shaped part 20e of the electrode body 20 located in between, it may be formed in the curved wall-shaped part 20f on the opposite side.

  In the electrode body 20 of the electricity storage device according to the embodiment and the modification, the cross-section changing portions 24 and 25 are formed in the positive electrode uncoated portion 21c and the negative electrode uncoated portion 22c. It may be formed at other positions in 22.

  The power storage element according to the embodiment and the modification includes one electrode body 20. However, the power storage element may include two or more electrode bodies.

  In the energy storage device according to the embodiment and the modification, the electrode body 20 has a configuration in which the strip-shaped positive electrode uncoated portion 21c and the negative electrode uncoated portion 22c are connected to the positive electrode current collector 50 and the negative electrode current collector 60, respectively. However, it is not limited to this. The electrode body has a tab that protrudes integrally from the positive electrode base material and the negative electrode base material and is not formed with the positive electrode active material layer and the negative electrode active material layer at the positions of the positive electrode uncoated part and the negative electrode uncoated part. It may be. The positive electrode current collector 50 and the negative electrode current collector 60 may be connected to the tab. At this time, the cross-sectional change parts 24 and 25 may be formed in a tab, and may be formed in places other than the tab in a positive electrode plate and a negative electrode plate.

  The power storage device according to the embodiment and the modification is a power storage device including the vertically wound electrode body 20, but the direction in which the end of the electrode body in the winding axis A direction is opposed to the lid body 12 of the container 10. It may be a power storage element including a horizontally wound electrode body on which the electrode body is disposed.

  In addition, embodiments constructed by arbitrarily combining the embodiment and the modified examples are also included in the scope of the present invention. For example, the cross-section changing parts 24 and 25 may be formed in one electrode body.

  In addition, the present invention can be realized not only as a power storage element as described above but also in a power storage device including one or more power storage elements. For example, the present invention can be realized as a power storage device including a plurality of power storage elements 100. The power storage device includes a plurality of power storage units arranged side by side, and each power storage unit includes, for example, a plurality of power storage elements 100 arranged in a line and electrically connected to each other. With the above-described configuration, the plurality of power storage elements 100 are used as one unit, and the quantity and arrangement of the power storage units can be selected in accordance with the electric capacity required for the power storage device, the shape and dimensions of the power storage device, and the like. A power storage device that includes a plurality of power storage elements 100 and has a high output can be mounted as a power source for a vehicle such as an electric vehicle (EV), a hybrid vehicle (HEV), and a plug-in hybrid vehicle (PHEV).

  The present invention can be applied to power storage elements such as lithium ion secondary batteries, power storage units, power storage devices, and the like.

20 Electrode body 21 Positive electrode plate (electrode plate)
21a Positive electrode substrate (electrode plate substrate)
21b Positive electrode active material layer (active material layer of electrode plate)
21c Positive electrode uncoated part (active material layer non-formation part)
21ca, 22ca edge (edge of electrode plate)
21d, 22d end (end of electrode plate)
22 Negative electrode (electrode plate)
22a Negative electrode substrate (electrode plate substrate)
22b Negative electrode active material layer (active material layer of electrode plate)
22c Negative electrode uncoated part (active material layer non-formed part)
23 Separator 23a, 23b Edge (Separator edge)
24, 25 Cross-section change part 50 Positive electrode current collector 50b, 60b Second fixing part 50b (connection part)
60 Negative electrode current collector 100 Storage element A Winding axis B Winding direction G Gap

Claims (8)

A power storage device comprising an electrode body formed by a wound electrode plate,
The electrode plate has a cross-section changing portion formed by a convex portion or a concave portion extending along the winding direction of the electrode plate at an end portion in the winding axis direction of the electrode plate in a curved portion of the electrode plate. Power storage element. The electricity storage device according to claim 1, wherein the cross-section changing portion is formed by a belt-like deformed portion of the electrode plate. The electric storage element according to claim 2, wherein the deformed portion is formed by a bent portion of the electrode plate. The electrode plate has a base material and an active material layer formed on the base material,
The electric storage element according to any one of claims 1 to 3, wherein the cross-section changing portion is located in a portion where the active material layer is not formed at an end portion of the base material in the winding axis direction. The electric storage element according to any one of claims 1 to 4, wherein the cross-section changing portion is disposed at least at the end portion of the electrode plate on the outermost periphery of the winding among the end portions of the electrode plate. A separator interposed between the electrode plates that are wound and overlapped with the electrode plates;
The power storage device according to claim 1, wherein the cross-section changing portion is disposed between an edge in the winding axis direction of the separator and an edge in the winding axis direction of the electrode plate. . And further comprising a current collector having a connection portion that forms a gap and is connected to the electrode body by sandwiching the electrode body in the gap,
The electrode body is inserted into the gap after undergoing deformation that becomes narrow in the direction intersecting the winding axis,
The electric storage element according to any one of claims 1 to 6, wherein the end portion of the electrode plate in which the cross-sectional change portion is located is located in the gap. It is a manufacturing method of the electrical storage element according to any one of claims 1 to 7,
Winding the electrode plate to produce the electrode body;
Forming the cross-section changing portion on the electrode plate when the electrode plate is wound or after the electrode plate is wound.

Images