JP2020021573A - Power storage element - Google Patents

Abstract

To provide a highly reliably power storage element including an electrode body having a wound electrode plate.SOLUTION: A power storage element includes an electrode body 400 including a wound positive electrode plate 410 and a wound negative electrode plate 420, and a spacer 500 having a projection 510 inserted into the center of winding 480 of the electrode body 400. The projection 510 includes a support 511 extended in the direction of a winding axis W, and a first wall 512 erected from the support 511 in the direction that intersects the direction of the winding axis W.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a power storage device including an electrode body having a wound electrode plate.

  Patent Literature 1 discloses a secondary battery including an assembled electrode body in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked with a separator interposed therebetween. The assembled electrode body has a positive electrode current collecting tab and a negative electrode current collecting tab provided in a protruding state. Each of the positive electrode current collecting tab and the negative electrode current collecting tab is bent so as to face the end surface of the assembled electrode body, and is connected to the conductive member. The secondary battery further includes an attachment member made of an insulating material attached to each tab group from the distal end side of the positive electrode current collection tab and the negative electrode current collection tab. The attachment member has a first covering portion and a second covering portion that sandwich the tab group and the conductive member. According to this configuration, the attachment member can prevent the free end of the tab from fluttering. As a result, sliding contact between the free ends of the tabs can be suppressed, and generation of foreign matter due to the sliding contact can be suppressed.

JP 2015-32549 A

  In the above-mentioned conventional secondary battery, an insulating member having a structure sandwiching a conductive member and a tab group provided in a protruding shape from the main body of the electrode body is disposed, so that generation of foreign matter (contamination) in the tab group is prevented. Is suppressed.

  However, in a power storage element such as a secondary battery, the source of contamination is not limited to the electrode body. For example, contamination can also occur at a joint between an electrode terminal and a conductive member such as a current collector. Specifically, when joining the electrode terminal and the conductive member, if the joining operation such as caulking is performed inside the container, contamination, which is metal powder or metal pieces, occurs during the joining operation. I do. In this case, the contamination remains at the joint portion, and for example, after the assembly of the electric storage element is completed, the contamination may move in the electrolytic solution and enter the inside of the electrode body.

  In particular, in the case of a wound electrode body having a wound electrode plate, there is a hollow portion (wound center portion) in a central portion through which a winding axis passes, so that contamination is generated inside the electrode body. It has a structure that is easy to invade. When contamination enters the inside of the electrode body, there is a high possibility that a defect such as a slight short circuit caused by the contamination occurs in the electrode body.

  The present invention has been made in consideration of the above-described conventional problems, and has as its object to provide a power storage element including an electrode body having a wound electrode plate and having high reliability.

  In order to achieve the above object, an energy storage element according to one embodiment of the present invention includes an electrode body having a wound electrode plate, and a spacer having a projection inserted into a winding center of the electrode body. The projecting portion includes a support portion extending in the direction of the winding axis of the electrode body, and a first wall erected from the support portion in a direction intersecting the direction of the winding axis. And a part.

  According to this configuration, the L-shaped protrusion of the spacer is arranged at the center of the winding. Thereby, the contamination which has invaded the winding center can be blocked at the position of the first wall. As a result, the occurrence of problems such as a slight short-circuit due to contamination is suppressed. Therefore, a highly reliable power storage element can be obtained.

  In addition, the power storage element according to one embodiment of the present invention further includes a container accommodating the electrode body, and an electrode terminal fixed to the container, wherein the first wall portion includes the electrode terminal from the support portion. It may be set up toward the side where it is arranged.

  As described above, when the power storage element includes the electrode terminal fixed to the container, contamination is likely to occur due to a joining operation such as caulking for connecting the electrode terminal and the current collector. Regarding this point, in the power storage element of this embodiment, the first wall portion of the projection is provided upright toward the electrode terminal. For this reason, the protruding portion can efficiently block the contamination generated during the joining operation.

  In the power storage element according to one embodiment of the present invention, the protruding portion may further include a second wall portion erected from the first wall portion in a direction opposite to a direction in which the support portion extends. Is also good.

  According to this configuration, the movement of the contamination blocked by the first wall portion is regulated by the support portion and the second wall portion which are arranged opposite to each other. This reduces the possibility that the contamination clogged by the first wall portion flows out of the protruding portion, and as a result, further reduces the possibility of occurrence of a defect such as a micro short circuit caused by the contamination. You.

  In the power storage element according to one embodiment of the present invention, the second wall may have a curved shape protruding in a direction away from the winding axis.

  According to this configuration, even if the second wall portion comes into contact with the innermost peripheral surface of the electrode body (the inner surface of the winding center portion), the second wall portion has a curved shape along the inner surface. The possibility that the second wall portion damages the electrode body is low. That is, the practicality of the spacer for improving the reliability of the power storage element is improved.

  In the power storage element according to one embodiment of the present invention, the protruding portion may further include a third wall portion erected from the second wall portion in a direction toward the support portion.

  According to this configuration, since the third wall is erected from the second wall toward the support, the possibility of the contamination blocked by the first wall returning in the opposite direction is reduced. . Further, when the third wall portion is provided upright at the tip portion of the second wall portion, for example, the possibility that the tip portion of the second wall portion damages the inner side surface of the winding center portion is reduced. That is, the practicality of the spacer for improving the reliability of the power storage element is improved.

  ADVANTAGE OF THE INVENTION According to this invention, it is an electric storage element provided with the electrode body which has a wound electrode plate, and can provide a highly reliable electric storage element.

FIG. 3 is a perspective view illustrating an appearance of a power storage element according to an embodiment. FIG. 3 is a perspective view showing components arranged in a container of the power storage element according to the embodiment. FIG. 2 is a perspective view illustrating an appearance of a current collector according to the embodiment. It is a perspective view which shows the structure outline of the electrode body which concerns on embodiment. It is an expansion perspective view of the spacer concerning an embodiment. FIG. 4 is a cross-sectional view for explaining a function of a protrusion of the spacer according to the embodiment. FIG. 9 is a side view illustrating a configuration of a spacer according to a first modification of the embodiment. FIG. 14 is a perspective view illustrating a configuration of a spacer according to a second modification of the embodiment.

  Hereinafter, power storage elements according to embodiments and modifications of the present invention will be described with reference to the drawings. Each drawing is a schematic diagram, and is not necessarily strictly illustrated.

  Each of the embodiments and modifications described below shows a specific example of the present invention. The shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, the order of the manufacturing steps, and the like shown in the following embodiments and modified examples are merely examples, and do not limit the present invention. Further, among the components in the following embodiments and modified examples, components that are not described in independent claims indicating the highest concept are described as arbitrary components.

  Further, in the following embodiments and the claims, expressions indicating relative directions or postures, such as parallel and orthogonal, may be used, but these expressions are strictly the directions or postures. Not including the case. For example, “the two directions are parallel” means not only that the two directions are completely parallel, but also that they are substantially parallel, that is, including, for example, a difference of about several percent. Also means. In the following description, for example, the plus side in the X-axis direction indicates the side to which the arrow of the X-axis points, and the minus side in the X-axis direction indicates the side opposite to the plus side in the X-axis direction. The same applies to the Y-axis direction and the Z-axis direction.

(Embodiment)
[1. General description of storage element]
First, a general description of power storage device 10 according to the embodiment will be given with reference to FIGS. FIG. 1 is a perspective view illustrating an appearance of a storage element 10 according to the embodiment. FIG. 2 is a perspective view showing components arranged in container 100 of power storage device 10 according to the embodiment. FIG. 3 is a perspective view illustrating an appearance of the current collector 120 according to the embodiment. In FIG. 1 and other drawings described below, a dashed line denoted by a reference symbol W represents a winding axis of the electrode body 400. The winding axis W is a virtual axis serving as a central axis when winding an electrode plate or the like, and is a straight line parallel to the Y axis passing through the center of the electrode body 400 in the present embodiment. That is, in the present embodiment, “direction of the winding axis W” is synonymous with “Y-axis direction”.

  The storage element 10 is a secondary battery that can charge and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. For example, the power storage element 10 is a power source for a vehicle (or for a mobile body) such as an electric vehicle (EV), a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV), a power source for an electronic device, or a power source for power storage. Applicable to etc. In some cases, power storage element 10 is mounted on a vehicle such as a gasoline-powered vehicle or a diesel-powered vehicle as a battery for starting an engine. The storage element 10 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. Further, power storage element 10 may be a primary battery that can use the stored electricity without the user having to charge.

  As shown in FIG. 1, power storage element 10 includes container 100, negative electrode terminal 200, and positive electrode terminal 300. As shown in FIG. 2, a current collector 120 on the negative electrode side, a current collector 130 on the positive electrode side, and an electrode body 400 are housed inside the container 100.

  Energy storage device 10 further includes spacers 500 arranged at both ends in the direction of winding axis W of electrode body 400. The spacer 500 according to the present embodiment has a spacer body 501 and a protruding portion 510 inserted into the winding center 480 of the electrode body 400. Details of the configuration of the spacer 500 will be described later with reference to FIGS.

  The power storage element 10 may include, in addition to the above components, a gas discharge valve for releasing the pressure in the container 100 when the pressure is increased, or an insulating film surrounding the electrode body 400 and the like. Good. A liquid such as an electrolytic solution (a non-aqueous electrolyte) is sealed inside the container 100 of the power storage element 10, but the liquid is not shown. The type of the electrolytic solution sealed in the container 100 is not particularly limited as long as the performance of the electric storage element 10 is not impaired, and various types can be selected.

  The container 100 includes a container body 111 having a rectangular tubular shape and having a bottom, and a lid 110 that is a plate-like member that closes an opening of the container body 111. Further, the container 100 has a structure in which the lid 110 and the container body 111 are welded or the like after the electrode body 400 or the like is housed inside, thereby sealing the inside. The electrode body 400 is a power storage element (power generation element) that includes a positive electrode plate, a negative electrode plate, and a separator and can store electricity. The detailed configuration of the electrode body 400 will be described later with reference to FIG.

  The negative electrode terminal 200 is an electrode terminal electrically connected to the negative electrode plate of the electrode body 400 via the current collector 120. The positive electrode terminal 300 is an electrode terminal electrically connected to the positive electrode plate of the electrode body 400 via the current collector 130. The negative electrode terminal 200 and the positive electrode terminal 300 are attached to the lid 110 disposed above the electrode body 400 via a gasket (not shown) having an insulating property.

  The current collector 120 is disposed between the negative electrode side end of the electrode body 400 and the wall surface of the container body 111 of the container 100, and has electrical conductivity electrically connected to the negative electrode terminal 200 and the negative electrode of the electrode body 400. It is a member having rigidity.

  The current collector 130 is disposed between the positive electrode side end of the electrode body 400 and the wall surface of the container body 111 of the container 100, and has electrical conductivity electrically connected to the positive electrode terminal 300 and the positive electrode of the electrode body 400. It is a member having rigidity.

  Specifically, current collectors 120 and 130 are fixed to lid 110. In addition, the current collector 120 is joined to a negative end of the electrode body 400, and the current collector 130 is joined to a positive end of the electrode body 400. In the present embodiment, each of current collectors 120 and 130 is bonded to electrode body 400 by ultrasonic bonding. Here, in the present embodiment, the configurations of current collector 120 and current collector 130 are substantially the same. Therefore, the configuration of the current collector 120 on the negative electrode side will be described with reference to FIG. 3, and the description of the configuration of the current collector 130 on the positive electrode side will be omitted.

  As shown in FIG. 3, current collector 120 in the present embodiment has a pair of legs 122 arranged so as to sandwich the negative end of electrode body 400 from both sides. The pair of legs 122 is a long portion extending from an end of the terminal connection portion 121 of the current collector 120. The terminal connection part 121 is a part connected to the negative electrode terminal 200. For example, the rivet (shaft portion) provided on the negative electrode terminal 200 is swaged in a state where the rivet penetrates the through hole 121 a of the terminal connection portion 121, so that the negative electrode terminal 200 and the current collector 120 are connected. The pair of legs 122 is joined to the negative end of the electrode body 400 by ultrasonic bonding. Thereby, the current collector 120 is electrically connected to the negative electrode of the electrode body 400. In addition, as a method of joining the electrode body 400 and the current collectors 120 and 130, a method such as resistance welding, laser welding, or clinch joining may be adopted other than the ultrasonic joining.

[1-1. Basic configuration of electrode body]
Next, a basic configuration of the electrode body 400 included in the electric storage element 10 configured as described above will be described with reference to FIG. FIG. 4 is a perspective view illustrating a schematic configuration of the electrode body 400 according to the embodiment. In FIG. 4, elements (laminated elements) such as stacked and wound electrode plates are partially developed and shown.

  The electrode body 400 is an example of an electrode body having a wound electrode plate. Specifically, the electrode body 400 is formed by winding an electrode plate and a separator around a core 460. Further, as shown in FIG. 4, electrode body 400 has a flat shape in a direction orthogonal to winding axis W (in the Z-axis direction in the present embodiment). That is, when viewed from the direction of the winding axis W, the electrode body 400 has an elliptical shape as a whole, and a straight portion of the elliptical shape is flat, and a curved portion of the elliptical shape is curved. Become. For this reason, the electrode body 400 has a pair of opposed curved ends (portions opposed in the Z-axis direction with the winding axis W interposed) and a pair of intermediate portions (winding portions) between the pair of curved ends. (A portion facing in the X-axis direction with the rotation axis W interposed therebetween).

  In this embodiment, the positive electrode plate 410 is formed by forming a positive electrode mixture layer 414 containing a positive electrode active material on a surface of a long strip-shaped metal foil (positive electrode base material layer 411) made of aluminum or an aluminum alloy or the like. It is. The negative electrode plate 420 is formed by forming a negative electrode mixture layer 424 containing a negative electrode active material on the surface of a long strip-shaped metal foil (negative electrode substrate layer 421) made of copper or a copper alloy. Further, in the present embodiment, separators 430 and 450 each have a microporous sheet made of a resin as a base material.

  More specifically, in the electrode body 400 configured as described above, the positive electrode plate 410 and the negative electrode plate 420 are wound while being shifted from each other in the direction of the winding axis W via the separator 430 or 450. The positive electrode plate 410 and the negative electrode plate 420 have, at the ends in the shifted directions, a portion of the base material layer where the mixture layer is not formed, that is, a portion where the mixture layer is not formed.

  Specifically, the positive electrode plate 410 has, at one end in the direction of the winding axis W (the end on the minus side in the Y-axis direction in FIG. 4), a mixture material layer non-forming portion 411 a in which the positive electrode mixture material layer 414 is not formed. have. In addition, the negative electrode plate 420 has, at the other end in the direction of the winding axis W (the end on the plus side in the Y-axis direction in FIG. 4), a mixture layer non-forming portion 421 a where the negative electrode mixture layer 424 is not formed. are doing.

  That is, the positive electrode side end is formed by the exposed metal foil (non-mixture layer forming portion 411a) layer of the positive electrode plate 410, and the exposed metal foil (non-mixture layer non-forming portion 421a) layer of the negative electrode plate 420 is formed by the layer. A negative electrode side end is formed. The positive end is joined to the current collector 130, and the negative end is joined to the current collector 120.

  The core 460 is formed in a tubular shape by winding a resin sheet made of, for example, polypropylene or polyethylene. Further, the core material is formed by winding the separator 430 forming the innermost circumference one or more times, and the separator 430, the negative electrode plate 420, the separator 450, and the positive electrode plate 410 are wound around the core material to form an electrode. A body 400 may be formed.

[1-2. Spacer and surrounding structure]
With respect to the electrode body 400 configured as described above, the spacer 500 is arranged on the side in the direction of the winding axis W. Hereinafter, the structure of the spacer 500 and the structural relationship between the spacer 500 and the electrode body 400 will be described with reference to FIGS. In the present embodiment, the spacers 500 are arranged on both the positive electrode side and the negative electrode side of the electrode body 400, but these two spacers 500 have the same structure. For this reason, the spacer 500 on the negative electrode side and its surrounding structure will be described with reference to FIGS. 5 and 6, and the description of the spacer 500 on the positive electrode side will be omitted.

  FIG. 5 is an enlarged perspective view of the spacer 500 according to the embodiment. In FIG. 5, in order to clearly show the configuration of the protruding portion 510 included in the spacer 500, the spacer 500 is separated from the electrode body 400 and a part of the spacer body 501 is shown in perspective. Illustration of other components around the spacer 500, such as the current collector 120, is omitted. FIG. 6 is a cross-sectional view for explaining the function of the protrusion 510 included in the spacer 500 according to the embodiment. In FIG. 6, the end on the negative electrode side in the VI-VI cross section of FIG. 1 is simply illustrated, and the container main body 111, the negative electrode terminal 200, the current collector 120, and the lid 110 are insulated from each other. Illustration of a gasket and the like is omitted. The spacer 500 is not illustrated in section but in side view.

  Spacer 500 provided in power storage element 10 according to the present embodiment protects the end of electrode body 400 in the direction of winding axis W, insulates the end from container 100, or regulates movement of electrode body 400. It is a member arranged for etc. The spacer 500 is made of, for example, polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), polyethylene terephthalate (PET), polyetheretherketone (PEEK), tetrafluoroethylene / perfluoroalkylvinylether (PFA), It is formed of an insulating material such as polytetrafluoroethylene (PTFE), polybutylene terephthalate (PBT), polyethersulfone (PES), ceramic, or a composite material thereof.

  As shown in FIGS. 5 and 6, power storage element 10 according to the embodiment includes electrode body 400 having wound electrode plates (in the present embodiment, positive electrode plate 410 and negative electrode plate 420); And a spacer 500 having a protruding portion 510 inserted into the winding center portion 480 of the winding 400. The protruding portion 510 includes a support portion 511 extending in the direction of the winding axis W and a first wall portion 512 erected from the support portion 511 in a direction intersecting the direction of the winding axis W. Have.

  As described above, in the present embodiment, the L-shaped protrusion 510 of the spacer 500 is disposed at the winding center 480. Thereby, as shown in FIG. 6, the contamination C that has entered the winding center portion 480 can be dammed at the position of the first wall portion 512. As a result, the occurrence of problems such as a slight short circuit caused by the contamination C is suppressed. Therefore, a highly reliable power storage element 10 can be obtained.

  Note that, in the present embodiment, more specifically, the first wall portion 512 is arranged in the thickness direction in the direction of the winding axis W. Therefore, as shown in FIG. 6, the contamination C that moves inward from the opening of the winding center portion 480 on the spacer 500 side can be more reliably or efficiently stopped.

  Further, the support portion 511 is supported by the spacer body 501 in a cantilever state, and the first wall portion 512 is supported by the support portion 511 in a cantilever state. That is, since the protruding portion 510 has a simple structure, it is easy to manufacture, for example. Further, the contamination C is a foreign substance such as a fine metal powder or a metal piece moving in the electrolytic solution. For this reason, the contamination C does not apply a mechanical load to the support portion 511 and the first wall portion 512 in the cantilevered state to such an extent that a structural problem occurs.

  Further, in the present embodiment, power storage element 10 includes container 100 (see FIG. 2) for housing electrode body 400, and negative electrode terminal 200 fixed to container 100, and first wall portion 512 includes support portion From 511, it stands up to the side where the negative electrode terminal 200 is arranged.

  Specifically, for example, as shown in FIG. 6, the negative electrode terminal 200 is fixed to the lid 110 of the container 100, and the first wall portion 512 is a side from the support portion 511 on which the negative electrode terminal 200 is arranged. Is set up toward the plus side in the Z-axis direction.

  Here, in the present embodiment, negative electrode terminal 200 and current collector 120 are connected by swaging. Specifically, as shown in FIG. 6, the shaft portion 210 of the negative electrode terminal 200 is swaged in a state of penetrating the through hole 121a of the current collector 120 (see FIG. 3). That is, the caulking portion 211 formed by caulking the tip of the shaft portion 210 is located inside the container 100. Therefore, the contamination C generated due to the rubbing of the metals during the caulking operation may remain in the vicinity of the caulked portion 211, though very slightly.

  In addition, when the power storage device 10 is disposed as, for example, one of the plurality of power storage devices 10 in a power storage module, or when the power storage device 10 is disposed as a power source of another device, the negative electrode terminal 200 is generally disposed in an upward posture. You. Therefore, when the contamination C remains near the caulking portion 211, the contamination C is likely to move downward due to the attractive force.

  Regarding this point, in power storage element 10 according to the present embodiment, first wall portion 512 of protruding portion 510 is erected toward negative electrode terminal 200. Therefore, the protruding portion 510 can efficiently block the contamination C generated at the time of caulking.

  Further, in the present embodiment, protruding portion 510 further has second wall portion 513 erected from first wall portion 512 in a direction opposite to the direction in which support portion 511 extends. Specifically, as shown in FIG. 6, the support portion 511 extends from the spacer body 501 toward the inside of the winding center portion 480 (toward the Y axis direction minus side). H, the second wall portion 513 is erected from the first wall portion 512 in the opposite direction (toward the Y axis direction plus side).

  According to this configuration, the movement of the contamination C blocked by the first wall portion 512 is restricted by the support portion 511 and the second wall portion 513 that are arranged to face each other. Thereby, the possibility that the contamination C blocked by the first wall portion 512 flows out of the protruding portion 510 is reduced, and as a result, there is a possibility that a defect such as a slight short circuit caused by the contamination C occurs. Is further reduced.

  The storage element 10 according to the embodiment has been described above, but the configuration of the spacer 500 included in the storage element 10 may be different from the configuration illustrated in FIGS. 2, 5, and 6. Therefore, a modified example of the spacer 500 will be described below with a focus on differences from the above-described embodiment.

(Modification 1)
FIG. 7 is a side view showing the configuration of the spacer 500a according to the first modification of the embodiment. Specifically, FIG. 7 shows a side view of a part of the spacer 500a including the protrusion 510a which is a characteristic part of the spacer 500a.

  As shown in FIG. 7, in the spacer 500 a according to the present modification, the protruding portion 510 has a third wall portion 514 erected from the second wall portion 513 toward the support portion 511.

  Since the third wall portion 514 is erected from the second wall portion 513 in the direction of the support portion 511 in this manner, the contamination C blocked by the first wall portion 512 moves in the opposite direction (Y-axis direction plus). Side direction) is reduced. In the present modification, the third wall portion 514 is erected at the tip end of the second wall portion 513. Therefore, for example, the tip end of the second wall portion 513 faces the inner surface of the winding center portion 480. The potential for damage is reduced.

(Modification 2)
FIG. 8 is a perspective view illustrating a configuration of a spacer 500b according to Modification 2 of the embodiment. Specifically, FIG. 8 shows a perspective view of a part of the spacer 500b including the protrusion 510b which is a characteristic part of the spacer 500b. Also, in FIG. 8, the spacer body 501 is shown in a state where the upper portion is cut out in order to clearly show the protruding portion 510b.

  As shown in FIG. 8, in the spacer 500b according to the present modification, the second wall portion 513b has a curved shape protruding away from the winding axis W. That is, the second wall portion 513b is curved along the inner side surface of the winding center portion 480.

  According to this configuration, even if the second wall portion 513b contacts the inner side surface of the winding center portion 480, the second wall portion 513b has a curved shape along the inner side surface. However, the possibility of damaging the electrode body 400 is low. That is, the practicality of the spacer 500b for improving the reliability of the power storage element 10 is improved.

  Note that the protruding portion 510b may further include a third wall portion erected from the second wall portion 513b toward the support portion 511. In this case, the movement of the contamination C blocked by the first wall portion 512 in the opposite direction is suppressed by the third wall portion.

  Here, the electrode body 400 has an oval shape as a whole when viewed from the direction of the winding axis W, as described above, and therefore, the winding center portion 480 also has an approximately oval shape. In this case, in the longitudinal direction of the winding central portion 480 when viewed from the direction of the winding axis W, the second wall portion 513b is formed between the winding axis W and the longitudinal end of the winding central portion 480. It can be described that the light emitting element is disposed between the light emitting elements and has a curved shape toward the end. The second wall portion 513b may be formed in a curved shape when viewed from the side (X-axis direction). That is, the second wall portion 513b may be curved such that the front end portion faces the direction of the support portion 511. In this case, like the third wall portion 514 in the first modification, the distal end portion functions as a portion that suppresses the movement of the contamination C blocked by the first wall portion 512 in the reverse direction.

(Other embodiments)
The storage element according to the present invention has been described based on the embodiments and the modifications. However, the present invention is not limited to the above embodiment and modifications. Various modifications conceivable by those skilled in the art may be applied to the above-described embodiments or modifications, or a form constructed by combining a plurality of components described above, without departing from the spirit of the present invention. Included in the range.

  For example, the spacer 500 according to the embodiment is disposed on both the positive electrode side and the negative electrode side of the electrode body 400, but the spacer 500 is disposed only on one of the positive electrode side and the negative electrode side of the electrode body 400. Is also good. Even in this case, an effect of suppressing the contamination C from entering the inside of the electrode body 400 is exerted on the positive electrode side or the negative electrode side where the spacer 500 is arranged.

  Further, the protrusion 510 included in the spacer 500 may not have the second wall 513. That is, since the protruding portion 510 has at least the support portion 511 and the first wall portion 512, it is possible to block the contamination C that is going to enter the inside of the electrode body 400.

  In addition, the spacer 500 may include a plurality of protrusions 510. For example, the protrusions 510 may be arranged at respective positions facing both ends in the longitudinal direction of the winding center 480 when viewed from the direction of the winding axis W. Further, for example, even when the protruding portion 510 is formed such that the protruding portion 510 is continuously arranged at a position facing the entire circumference of the winding center portion 480 when viewed from the direction of the winding axis W. Good. For example, when viewed from the direction of the winding axis W, the annular supporting portion 511 is disposed on the spacer body 501 and extends at the tip of the annular supporting portion 511 in a direction away from the winding axis W. A flange may be provided. Thus, the flange functions as the first wall portion 512. As a result, the effect of suppressing the contamination C from entering the inside of the electrode body 400 can be obtained in a wider range.

  Similarly to the spacer 500, if the member is a protrusion having a support portion and a first wall portion and having a protrusion inserted into the winding center portion 480, it is not a “spacer” but an “insulating member”, “ A member called an “insulating sheet” or a “protective sheet” may be used. That is, regardless of the name, any member having the same structure as the spacer 500 can be treated as a member equivalent to the spacer 500.

  Further, in the present embodiment, power storage element 10 includes only one electrode body 400, but the number of electrode bodies 400 included in power storage element 10 may be two or more. For example, when the power storage element 10 includes two electrode bodies 400, the spacer 500 includes a spacer body 501 having a size corresponding to the two electrode bodies 400 and two spacers 500 arranged at positions corresponding to the two electrode bodies 400. And two protrusions 510.

  Note that the various supplementary items for the spacer 500 described above may be applied to the spacers 500a and 500b according to the first and second modifications. Further, a mode constructed by arbitrarily combining the configurations described in the above embodiments is also included in the scope of the present invention.

  Further, the present invention can be realized not only as the above-described power storage element but also as a spacer included in the power storage element. Further, the present invention can be implemented as a power storage device including a plurality of the power storage elements.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a power storage element such as a lithium ion secondary battery.

DESCRIPTION OF SYMBOLS 10 Electric storage element 100 Container 300 Positive electrode terminal 400 Electrode body 480 Winding center part 500, 500a, 500b Spacer 501 Spacer main body 510, 510a, 510b Projection part 511 Support part 512 First wall part 513, 513b Second wall part 514 Third Wall

Claims (5)

An electrode body having a wound electrode plate,
A spacer having a protruding portion inserted into the winding center of the electrode body,
The protrusion is
A support portion extending in the direction of the winding axis of the electrode body,
A power storage element comprising: a first wall portion erected from the support portion in a direction intersecting the direction of the winding axis. Further, a container accommodating the electrode body, and an electrode terminal fixed to the container,
The power storage device according to claim 1, wherein the first wall portion is erected from the support portion toward a side where the electrode terminal is arranged. The power storage element according to claim 1, wherein the protruding portion further includes a second wall portion erected from the first wall portion in a direction opposite to a direction in which the support portion extends. The electric storage element according to claim 3, wherein the second wall has a curved shape protruding in a direction away from the winding axis. The power storage device according to claim 3, wherein the projecting portion further includes a third wall portion erected from the second wall portion in a direction toward the support portion.

Images