JP6682758B2 - Storage element - Google Patents

Description

  The present invention relates to a power storage element having a wound electrode body formed by winding a positive electrode, a negative electrode, and a separator.

  2. Description of the Related Art Conventionally, there is a power storage element including a battery such as a lithium-ion battery, which has a wound electrode body in which a positive electrode, a negative electrode, and a separator are laminated and wound (for example, see Patent Document 1). In the electricity storage device having such a wound electrode body, it is necessary to fix the outermost circumference so that the wound state does not loosen at the position of the winding end of the outermost circumference of the wound electrode body. A separator is generally arranged on the outermost periphery of the electrode body.At this time, an insulating tape such as an adhesive tape is used as a method for fixing the separator at the position of the winding end of the outermost periphery of the wound electrode body. There is a method to fix it.

JP-A-11-250873

  However, it is difficult to more reliably fix the outermost circumference of the electrode body while preventing the winding state of the electrode body from being loosened in the configuration in which the conventional insulating tape is used for fixing. Therefore, the fixing of the outermost peripheral portion is likely to be loosened, and a space (distance) between the positive electrode and the negative electrode of the spirally wound electrode body is likely to be open, which may lead to deterioration in the performance of the power storage element.

  Then, this invention is made | formed in view of such a situation, and an object of this invention is to provide the electrical storage element which can suppress that performance falls.

  In order to achieve the above object, a power storage element according to one embodiment of the present invention is a power storage element including an electrode body formed by winding a positive electrode, a negative electrode, and a separator, and the electrode body is wound. An insulating tape, which is wound around the electrode body along the outermost peripheral surface of the electrode body in the same direction as the above-described direction and is wound around the electrode body for one or more turns, and a part of the insulating tape is overlapped with the other portion and joined. .

  According to this, in the insulating tape, the electrode body is wound one or more times along the outermost peripheral surface of the electrode body, and a part of the insulating tape is overlapped with the other portion of the insulating tape and joined. Therefore, the insulating tape can more securely fix the outermost peripheral portion of the electrode body.

  Furthermore, since the insulating tape is wound in the same direction as the direction in which the electrode body is wound, when the insulating tape is wound around the electrode body, a tensile force is applied to the outermost circumference of the electrode body. The electrode body can be wound one or more times. That is, by winding the insulating tape around the electrode body while suppressing the loosening of the wound electrode body, the wound state of the electrode body can be maintained. Therefore, it is possible to suppress the performance deterioration of the power storage element.

  Further, for example, the separator may include a base material layer and a particle-containing layer containing particles, and the particle-containing layer may be arranged on the outermost peripheral surface of the electrode body.

  Here, the above-mentioned conventional technique also has the following problems. Even when heat is generated at an abnormal time, for the purpose of maintaining insulation between the positive electrode and the negative electrode, for example, a separator coated with a heat-resistant layer containing inorganic particles on one surface of the separator (hereinafter, "heat-resistant coating"). "Separator".) Has been devised. When such a heat-resistant coated separator is applied to a wound electrode body, the heat-resistant layer of the heat-resistant coated separator does not easily adhere to the adhesive tape because the heat-resistant layer contains particles, and the outermost peripheral portion is the adhesive tape. It is difficult to fix it with insulating tape. Therefore, the fixing of the outermost peripheral portion is likely to be loosened, and a space (distance) between the positive electrode and the negative electrode of the spirally wound electrode body is likely to be open, which may lead to deterioration in the performance of the power storage element.

  According to this embodiment, the insulating tape is wound around the outermost peripheral surface of the electrode body for one or more turns, and a part of the insulating tape is overlapped with another portion of the insulating tape which is easily adhered. It is joined. Therefore, since the insulating tape can fix the outermost peripheral portion of the electrode body, the wound state of the electrode body can be maintained. As a result, it is possible to prevent the winding-type electrode body from loosening, and it is possible to suppress the performance deterioration of the electricity storage device that employs the separator provided with the particle-containing layer.

  Further, for example, the insulating tape may be arranged on both sides of the electrode body in the winding axis direction of the electrode body.

  In this way, the insulating tape does not cover the entire outermost peripheral surface of the electrode body, and therefore the permeability of the electrolytic solution into the electrode body can be improved.

  Further, for example, the insulating tape may be arranged at a position where the distance from the edge of the separator in the winding axis direction of the electrode body is smaller than the width of the insulating tape.

  Therefore, it is possible to prevent the end portion in the winding axis direction of the electrode body from being turned up among the outermost end portions of the electrode body. As a result, the state in which the electrode body is wound more firmly can be maintained, and thus the performance deterioration of the electricity storage element can be further suppressed.

  Further, for example, an inner end portion of the insulating tape may be arranged on an outermost end portion in the winding direction of the electrode body.

  Therefore, when the insulating tape is wound around the electrode body, the insulating tape may be wound around the electrode body for one or more turns while pressing the outermost end portion of the separator (the outermost end portion of the electrode body). it can. In this way, by holding the outermost peripheral end so as not to loosen the electrode body and then winding the insulating tape, it is possible to maintain the wound state of the electrode body so that the electrode body does not loosen. Therefore, it is possible to further suppress the performance deterioration of the power storage element.

  Further, for example, the inner end portion of the insulating tape is arranged on the outermost peripheral surface in a region closer to the winding direction than the outermost end portion in the winding direction of the electrode body. Good.

  According to this, the insulating tape is wound one or more times around the electrode body, and the portion overlapping the insulating tape itself is arranged in a region on the winding direction side of the outermost end of the electrode body. You can In other words, the portion where the insulating tape itself overlaps and is thicker than the other portions can be arranged in a portion where the height is low among the steps generated due to the outermost periphery of the electrode body overlapping. The structure of the assembly of the body and the insulating tape can be made compact.

  According to the power storage element of the present invention, it is possible to prevent the performance of the power storage element from being degraded.

It is a perspective view which shows typically the external appearance of the electrical storage element which concerns on embodiment of this invention. FIG. 3 is a perspective view showing each constituent element included in the power storage element by separating the main body of the container of the power storage element according to the embodiment of the present invention. It is a figure for demonstrating the structure of an electrode body. It is a perspective view which shows the external appearance of an electrode body and an insulating tape. It is sectional drawing of an electrode body and an insulating tape. It is a figure for demonstrating the winding direction of an electrode body and an insulating tape. 9 is a perspective view showing appearances of an electrode body and an insulating tape according to Modification Example 1. FIG. FIG. 9 is a cross-sectional view of an electrode body and an insulating tape according to Modification Example 1.

  Hereinafter, an electric 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 preferred specific example of the present invention. Numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. Further, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept are described as arbitrary constituent elements. In addition, the dimensions and the like in each drawing are not strictly illustrated.

(Embodiment)
FIG. 1 is a perspective view schematically showing an external appearance of a power storage element 10 according to an embodiment of the present invention. FIG. 2 is a perspective view showing the respective constituent elements of the storage element 10 which are obtained by separating the container body 111 of the container 100 of the storage element 10 according to the embodiment of the present invention.

  The electricity storage device 10 is a secondary battery capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte battery such as a lithium ion secondary battery. For example, the storage element 10 is applied to an electric vehicle (EV), a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), or the like. The storage element 10 is not limited to the non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery or a capacitor.

  As shown in these drawings, the electricity storage device 10 includes a container 100, a positive electrode terminal 200, a negative electrode terminal 300, and a container 100. A positive electrode current collector 120, a negative electrode current collector 130, and an electrode body 140 are housed inside the container 100.

  Further, a liquid such as an electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100 of the electricity storage device 10, but the liquid is not shown. As the electrolytic solution sealed in the container 100, there are no particular restrictions on the type of electrolytic solution as long as it does not impair the performance of the electricity storage device 10, and various electrolytic solutions can be selected.

  The container 100 includes a container main body 111 having a rectangular tubular shape and a bottom, and a lid 110 that is a plate-like member that closes the opening of the container main body 111. Further, the container 100 is capable of hermetically sealing the inside by housing the electrode body 140 and the like and then welding the lid 110 and the container body 111. The material of the lid 110 and the container body 111 is not particularly limited, but it is preferably a weldable metal such as stainless steel, aluminum, or aluminum alloy.

  The electrode body 140 includes a positive electrode, a negative electrode, and a separator, and is a member that can store electricity. Specifically, the electrode body 140 is formed by layering a separator sandwiched between a negative electrode and a positive electrode so as to have an oval shape as a whole. Although the elliptical shape is shown as the shape of the electrode body 140 in the same drawing, it may be circular or elliptical. The detailed configuration of the electrode body 140 will be described later.

  The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode of the electrode body 140, and the negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode of the electrode body 140. That is, the positive electrode terminal 200 and the negative electrode terminal 300 lead the electricity stored in the electrode body 140 to the external space of the electricity storage device 10 and generate electricity in the inner space of the electricity storage device 10 to store the electricity in the electrode body 140. Is a metal electrode terminal for introducing. Further, the positive electrode terminal 200 and the negative electrode terminal 300 are attached to the lid 110 arranged above the electrode body 140.

  The positive electrode current collector 120 is disposed between the positive electrode of the electrode body 140 and the side wall of the container 100, and has electrical conductivity and rigidity that is electrically connected to the positive electrode terminal 200 and the positive electrode of the electrode body 140. Is. The positive electrode current collector 120 is made of the same material as the positive electrode of the electrode body 140, and is specifically formed of aluminum or an aluminum alloy.

  The negative electrode current collector 130 is disposed between the negative electrode of the electrode body 140 and the side wall of the container 100, and is electrically conductive and rigidly connected to the negative electrode terminal 300 and the negative electrode of the electrode body 140. Is. The negative electrode current collector 130 is made of the same material as the negative electrode of the electrode body 140, and is specifically formed of copper or a copper alloy.

  FIG. 3 is a diagram for explaining the structure of the electrode body 140. FIG. 4 is a perspective view showing appearances of the electrode body 140 and the insulating tape 150. FIG. 5 is a cross-sectional view of the electrode body 140 and the insulating tape 150. Specifically, FIG. 5A is a view showing an AA cross section of the electrode body 140 and the insulating tape 150 of FIG. 4, and FIG. 5B is a region of FIG. It is an enlarged view which expanded A1.

  As shown in FIGS. 3 to 5, the electrode body 140 is formed by stacking and winding a positive electrode 141 and a negative electrode 142 on the surface of which an active material is applied, and separators 143 and 144. That is, the electrode body 140 is wound in a state where the positive electrode 141, the first separator 143, the negative electrode 142, and the second separator 144 are laminated in this order so that the cross section becomes an elliptical shape. It is formed. Then, as shown in FIG. 4, the outermost circumference (the last one circumference) of the electrode body 140 formed by winding is a plurality of positions (in the present embodiment, in the winding axis direction of the electrode body) in the X-axis direction. It is fixed by insulating tape 150 at two positions.

  The positive electrode 141 is formed by forming a positive electrode active material layer on the surface of a long strip-shaped positive electrode current collector foil made of aluminum or an aluminum alloy. In addition, the positive electrode 141 used in the electricity storage device 10 according to the present invention is not different from the conventionally used one, and a commonly used one can be used.

  The negative electrode 142 is formed by forming a negative electrode active material layer on the surface of a strip-shaped negative electrode current collector foil made of copper or a copper alloy. It should be noted that the negative electrode 142 used in the electricity storage device 10 according to the present invention is not particularly different from the conventionally used one, and a commonly used one can be used.

  The first separator 143 and the second separator 144 are long strip-shaped separators arranged between the positive electrode 141 and the negative electrode 142. The first separator 143 and the second separator 144 are heat-resistant coating separators each including a base material layer 143a, 144a and a particle-containing layer 143b, 144b.

  The base material layers 143a and 144a are microporous sheets made of a thermoplastic resin.

  The particle-containing layers 143b and 144b are layers formed on one surface of the base material layers 143a and 144a and made of different materials from the base material layers 143a and 144a. In the present embodiment, the particle-containing layers 143b and 144b are layers coated on one surface of the base material layers 143a and 144a. Here, the particle-containing layers 143b and 144b are heat-resistant layers containing a mixture of inorganic particles such as alumina and a binder such as polyvinylidene fluoride (PVdF) or a heat-resistant resin such as polydivinylbenzene (PDVB) or polyamide ( Inorganic coating layer). The particle-containing layers 143b and 144b may contain organic particles instead of inorganic particles. Moreover, the particle-containing layers 143b and 144b may be arranged on both surfaces of the base material layers 143a and 144a.

  That is, each of the first separator 143 and the second separator 144 has the base material layers 143a and 144a and the particle-containing layers 143b and 144b arranged on the base material layers 143a and 144a and containing particles. The first separator 143 and the second separator 144 are laminated so that the particle-containing layers 143b and 144b face the positive electrode 141, and the base material layers 143a and 144a face the negative electrode 142.

  A winding core 145 made of polypropylene, polyethylene, or the like is arranged on the innermost circumference of the electrode body 140. The electrode body 140 is formed by winding the positive electrode 141, the first separator 143, the negative electrode 142, and the second separator 144 while the first separator 143 and the second separator 144 are welded and fixed to the winding core 145. To be done.

  Further, the outermost peripheral surface (that is, the outermost peripheral surface) of the electrode body 140 is constituted by the particle-containing layer 144b of the second separator 144 as shown in FIGS. 3 and 4. That is, in the electrode body 140, the second separator 144 is wound around the outermost circumference of the electrode body 140 one or more times, and the end portion 144c on the outermost circumference side of the second separator 144 is directly attached to another portion of the second separator 144 itself. It is an overlapping structure.

  The insulating tape 150 is a long strip tape whose one surface has adhesiveness (adhesiveness). The insulating tape 150 is attached along the outermost peripheral surface of the electrode body 140 such that a part of the insulating tape 150 overlaps the other part of the insulating tape 150 while being wound around the electrode body 140 for one or more turns. By being joined together. Further, the insulating tape 150 is arranged such that the adhesive surface contacts the outermost peripheral surface of the electrode body 140. That is, the insulating tape 150 maintains the wound state of the electrode body 140 by forming the insulating tape 150 in a ring shape along the outermost peripheral surface of the electrode body 140.

  More specifically, the inner end 151 of the insulating tape 150 is disposed on the outermost end 144c of the second separator 144 in the winding direction of the electrode body 140. The insulating tape 150 has a structure in which the outer end portion 152 is bonded onto the inner end portion 151 while being wound around the electrode body 140 once.

  Here, the outermost peripheral end 144c of the second separator 144 is a portion in a region within a predetermined range R1 from the outermost peripheral edge E1 of the second separator 144. The predetermined range R1 is, for example, a range having a length that is 1 to 2 times the width W1 of the insulating tape 150. Here, if the width W1 of the insulating tape 150 is too thin, twisting or winding misalignment of the insulating tape itself may occur. Therefore, the width W1 is preferably 5 to 50 mm, and further 20 to 40 mm. More preferably. Further, by setting the width of the insulating tape within the above numerical range, the electrolytic solution can easily permeate and the insulating tape can be prevented from being wound in the state where wrinkles are generated.

  The insulating tape 150 is arranged on both sides of the electrode body 140 in the winding axis direction. Specifically, in the insulating tape 150, the distance L1 from the end edge of the second separator 144 in the winding axis direction of the electrode body 140 (that is, the X axis direction) is smaller than the width W1 of the insulating tape 150. It is arranged. That is, of the two insulating tapes 150, the insulating tape 150 arranged on the minus side in the X-axis direction has a distance L1 from the edge on the minus side in the X-axis direction of the second separator 144 smaller than the width W1. The insulating tape 150 disposed on the positive side in the X-axis direction is located at a position where the distance L1 from the edge of the second separator 144 on the positive side in the X-axis direction is smaller than the width W1. It is arranged.

  The insulating tape 150 is wound in the same direction as the winding direction of the positive electrode 141, the negative electrode 142, and the separators 143, 144, which are the constituent elements of the electrode assembly 140.

  FIG. 6 is a diagram for explaining the winding directions of the electrode body 140 and the insulating tape 150. Specifically, FIG. 6A is a diagram for explaining the winding direction when forming the electrode body 140, and FIG. 6B is a view for winding the insulating tape 150 around the electrode body 140. It is a figure for demonstrating the winding direction at the time of turning.

  As shown in FIG. 6A, the electrode body 140 is formed by winding the positive electrode 141, the negative electrode 142, and the separators 143 and 144 counterclockwise when viewed from the X-axis direction plus side. ing. Moreover, as shown in FIG. 6B, the insulating tape 150 is formed by being wound counterclockwise with respect to the electrode body 140 when viewed from the plus side in the X-axis direction. That is, as shown in FIGS. 6A and 6B, the winding direction in which the electrode body 140 is formed and the winding direction of the insulating tape 150 are the same direction.

  The winding direction may be defined as follows.

  When the wound object is traced from the inside position to the outside position of the wound object, the winding direction is set so that the winding direction is counterclockwise and the direction is clockwise. The winding direction of the winding may be the right direction.

  Further, the winding direction may be defined by the circumferential direction in which the outermost end edge (end surface) of the wound wound article faces. That is, in the electrode body 140, the outermost peripheral edge of the second separator 144 is leftward because it is facing leftward in the circumferential direction. Further, in the insulating tape 150, the edge of the insulating tape 150 at the outermost periphery of the wound winding material is directed leftward because it is directed leftward in the circumferential direction.

  As described above, according to the present embodiment, insulating tape 150 is a portion of insulating tape 150 that is a part of insulating tape 150 wound around electrode body 140 at least once along the outermost peripheral surface of electrode body 140. End portion 152 is adhered onto the inner end portion 151 which is another portion of the insulating tape 150 itself which is easily adhered. Therefore, since the insulating tape 150 can fix the outermost peripheral portion of the electrode body 140, it is possible to maintain the wound state of the electrode body 140. As a result, it is possible to prevent the winding-type electrode body 140 from loosening, and to reduce the performance of the electricity storage device 10 that employs the separators 143 and 144 provided with the particle-containing layers 143b and 144b that are heat-resistant layers. Can be suppressed. Further, in the electricity storage device 10, even if the separators 143 and 144 provided with the particle-containing layers 143b and 144b that are heat-resistant layers are adopted, the performance deterioration of the electricity storage device 10 can be suppressed. Even if there is, safety can be secured.

  Further, according to the present embodiment, insulating tape 150 is wound in the same direction as the direction in which electrode body 140 is wound. Therefore, when the insulating tape 150 is wound around the electrode body 140, the insulating tape 150 can be wound around the electrode body 140 for one or more turns while applying a tensile force to the outermost circumference of the electrode body 140. That is, when the insulating tape 150 is wound around the electrode body 140, the insulating tape 150 can be wound around the electrode body 140 while suppressing the winding-type electrode body 140 from loosening. Can be maintained.

  Further, according to the present embodiment, the inner end 151 of the insulating tape 150 is arranged on the outermost end 144c of the second separator 144 in the winding direction. Therefore, when the insulating tape 150 is wound around the electrode body 140, the insulating tape 150 is pressed against the electrode body 140 while pressing the outermost peripheral edge portion 144c of the second separator 144 (that is, the outermost peripheral edge portion of the electrode body 140). One or more turns can be wound around 140. As described above, the insulating tape 150 can be wound after pressing the outermost end portion so that the electrode body 140 does not loosen, so that the electrode body 140 is wound so that the electrode body 140 does not loosen. You can maintain a good condition.

  In addition, according to the present embodiment, insulating tape 150 is arranged on both sides of electrode body 140 in the winding axis direction. As described above, the insulating tape 150 does not cover the entire outermost peripheral surface of the electrode body 140, and thus the permeability of the electrolytic solution into the electrode body 140 can be improved.

  Further, according to the present embodiment, in insulating tape 150, distance L1 from the edge of second separator 144 in the winding axis direction (X axis direction) of electrode body 140 is greater than width W1 of insulating tape 150. It is located in a smaller position. Therefore, it is possible to prevent the outermost end 144c of the electrode body 140 from being turned up. Thereby, the state in which the electrode body 140 is wound more firmly can be maintained.

(Modification 1)
In the electricity storage device 10 in the above-described embodiment, the inner end 151 of the insulating tape 150 is arranged on the outermost end 144c of the second separator 144 in the winding direction, but the present invention is not limited to this.

  FIG. 7 is a perspective view showing the outer appearance of the electrode body 140 and the insulating tape 250 according to the first modification. FIG. 8 is a cross-sectional view of the electrode body 140 and the insulating tape 250 according to the first modification. Specifically, (a) of FIG. 8 is a view showing a BB cross section of the electrode body 140 and the insulating tape 250 of FIG. 7, and (b) of FIG. 8 is a region of (a) of FIG. It is an enlarged view which expanded A2.

  As shown in FIGS. 7 and 8, in the electrode body 140 and the insulating tape 250 according to the first modification, the inner end 251 of the insulating tape 250 is the outermost end of the outermost peripheral surface of the electrode body 140. It is arranged on the region 144d on the winding direction side of the portion 144c.

  Here, the area 144d is a winding start area of the outermost peripheral surface of the electrode body 140. More specifically, the region 144d is a region that is adjacent to the outermost edge E1 of the second separator 144 on the winding direction side, and is a region within a predetermined range R2 from the edge E1. Further, the predetermined range R2 is, for example, a range having a length which is 1 to 2 times the width W1 of the insulating tape 250. Note that the configuration of the electrode body 140 is similar to that of the electrode body 140 of the embodiment, so description thereof will be omitted.

  According to the electrode body 140 and the insulating tape 250 according to the modified example 1, the insulating tape 250 is wound around the electrode body 140 for one or more turns, and the portion overlapping the insulating tape 250 itself is located on the outermost peripheral side of the electrode body 140. It can be arranged in the region 144d on the winding direction side of the end portion 144c. That is, a portion of the insulating tape 250 that is thicker than the other portion due to the inner end 251 and the outer end 252 of the insulating tape 250 overlaps with each other among the steps generated by the outermost periphery of the electrode body 140 overlapping. It can be placed at a low height. Therefore, the structure of the assembly of the electrode body 140 and the insulating tape 250 can be made compact.

  Further, according to the electrode body 140 and the insulating tape 250 according to the modified example 1, the inner end 251 of the insulating tape 250 is on the same surface as the surface on which the outermost end 144 c of the electrode body 140 is arranged. Can be placed adjacent to each other. Therefore, the insulating tape 250 can be wound around the electrode body 140 so that the insulating tape 250 does not have a step. As a result, at least the portion where the insulating tape 250 is adhered to the insulating tape 250 itself can be made substantially flat, and the state in which the electrode body 140 is wound more firmly can be maintained.

(Modification 2)
Although two insulating tapes 150 and 250 are provided on the electrode body 140 in the above-described embodiment and its modification, the insulating tapes 150 and 250 are not limited to two, and one insulating tape may be provided. The configuration may be such that three or more are provided. In addition, the insulating tapes 150 and 250 are positioned such that the distance L1 from the edge of the second separator 144 in the winding axis direction (X-axis direction) of the electrode body 140 is smaller than the width W1 of the insulating tapes 150 and 250. It may not be arranged. Further, the insulating tapes 150 and 250 may be wide insulating tapes, for example, a width larger than half the width of the second separator 144.

(Modification 3)
In the above-mentioned embodiment and its modified examples, the insulating tapes 150 and 250 are tapes having adhesiveness (adhesiveness) on one side, but the entire one side may not have adhesiveness. It suffices that only the outer end portion of the insulating tape wound around the 140 for one or more turns has adhesiveness. Further, for example, only the outer peripheral surface of the inner end portion of the insulating tape may have adhesiveness. Also, an insulating tape having adhesiveness on both sides may be adopted.

(Modification 4)
In the above-described embodiment and its modifications, the first separator 143 and the second separator 144 are heat-resistant coating separators each including a base material layer 143a, 144a and a particle-containing layer 143b, 144b, but the particle-containing A separator that does not include the layers 143b and 144b may be used. Further, only one of the first separator and the second separator may be provided with the particle-containing layer.

(Modification 5)
In the above-described embodiment and its modification, the insulating tape 150 is joined by overlapping and adhering a part of the insulating tape 150 to another portion, but it may be joined by another joining method such as welding. Good.

(Modification 6)
Although the insulating tapes 150 and 250 are wound around the electrode body 140 once in the above-described embodiment and its modifications, the insulating tapes 150 and 250 are wound around the electrode body 140 once or more. May be.

(Modification 7)
In the above-described embodiment and its modification, the insulating tapes 150 and 250 are configured such that the outer end portions 152 and 252 are adhered to the surfaces on the inner end portions 151 and 251. Not limited to the configuration in which the electrodes are bonded to each other, the electrodes may not be bonded at the ends of the insulating tape as long as they are wound around the electrode body 140 in a state of being wound one or more times.

(Modification 8)
In the above-described embodiment and its modified example, the insulating tapes 150 and 250 have a configuration in which the position in the X-axis direction is spirally wound at different positions in the circumferential direction, but the invention is not limited to the spiral shape. In addition, the structure may be spirally wound such that the position in the X-axis direction differs depending on the position in the circumferential direction.

  Although the power storage elements according to the embodiments and the modifications thereof of the present invention have been described above, the present invention is not limited to the above embodiments and the modifications thereof. That is, it should be considered that the embodiments and the modifications thereof disclosed this time are exemplifications in all points and not restrictive. The scope of the present invention is shown not by the above description but by the scope of claims for patent, and it is intended that all modifications within the scope and meaning equivalent to the scope of claims for patent are included.

  Further, a mode constructed by arbitrarily combining the above-mentioned embodiment and the above-mentioned modified examples is also included in the scope of the present invention.

  The power storage element according to one embodiment of the present invention is useful as a power storage element or the like that can suppress deterioration in performance in a structure including an electrode body having a separator provided with a layer containing particles.

10 electricity storage element 100 container 110 lid body 111 container body 120 positive electrode current collector 130 negative electrode current collector 140 electrode body 141 positive electrode 142 negative electrode 143 first separator 143a base material layer 143b particle-containing layer 144 second separator 144a base material layer 144b particles Containing layer 144c End 144d Region 150, 250 Insulation tape 151, 251 Inner end 152, 252 Outer end 200 Positive electrode terminal 300 Negative electrode E1 Edge R1, R2 Predetermined range W1 Width

Claims (4)

A storage element comprising a positive electrode, a negative electrode, and an electrode body formed by being wound so that the separator has an oval shape when viewed from the winding axis direction,
In a flat region of the outermost peripheral surface, the electrode body is wound one or more times along the outermost peripheral surface of the electrode body in the same direction as the winding direction. With an insulating tape whose part overlaps with the other part and is joined ,
Ends of the positive electrode, the negative electrode, and the end of winding of each of the separators are arranged on a flat surface of the electrode body,
The end of the winding end of the separator is located in a region on the winding direction side of the electrode body with respect to the end of the winding end of the positive electrode and the negative electrode,
The inner end of the insulating tape is disposed at the end of the winding end of the separator,
An electric storage element in which an outer end of the insulating tape is fixed to an inner end of the insulating tape . The separator has a base material layer and a particle-containing layer containing particles,
The electricity storage device according to claim 1, wherein the particle-containing layer is arranged on an outermost peripheral surface of the electrode body. The electricity storage device according to claim 1, wherein the insulating tape is arranged on both sides of the electrode body in a winding axis direction of the electrode body. The said insulating tape is arrange | positioned in the position where the distance from the edge of the said separator in the winding axis direction of the said electrode body becomes smaller than the width of the said insulating tape. The electricity storage device described.

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