JP7435642B2 - Energy storage element - Google Patents

Description

The present invention relates to a power storage element that includes an electrode body formed by winding an electrode plate and a container that accommodates the electrode body.

The electrode body included in the electricity storage element is formed by, for example, winding layers arranged in layers such that a separator is sandwiched between a positive electrode plate and a negative electrode plate. Techniques have been disclosed for improving the resistance to impact and the like of a power storage element including such a wound electrode body. For example, in the power storage element described in Patent Document 1, resistance to impact and the like is improved by a reinforcing member extending in the direction in which the pair of current collectors are arranged and protruding from the pair of current collectors.

Japanese Patent Application Publication No. 2015-162387

When a member (for example, referred to as an "auxiliary member") for improving impact resistance or vibration resistance is placed in the container as in the above-mentioned conventional technology, the auxiliary member is placed directly on the electrode body, for example. It is preferably placed in operative contact with the electrode body. However, this is disadvantageous, for example, from the viewpoint of avoiding damage to the electrode body by auxiliary members. In other words, how to arrange the auxiliary member within the container of the power storage element is not an easy problem, as it also has to be balanced with the effect of improving resistance to vibrations and the like.

The present invention was made by the inventor of the present application newly paying attention to the above-mentioned problem, and provides a power storage element comprising an electrode body formed by winding an electrode plate and a container housing the electrode body. The purpose is to provide a highly reliable power storage element.

In order to achieve the above object, a power storage element according to one aspect of the present invention includes an electrode body formed by winding an electrode plate, a container housing the electrode body, an inner surface of the container, and the electrode body. and an auxiliary member disposed between the electrode body, the electrode body having a flat portion, and the auxiliary member being disposed on the side of the transverse direction of a cross section perpendicular to the winding axis direction of the electrode body. Further, a flat support part and a convex part provided on the support part to press the flat part of the electrode body, the entire circumference of the convex part when viewed from the direction in which the convex part protrudes. a convex portion disposed such that a flat portion of the support portion is located at the convex portion; a regulating portion, the flat portion of the support portion extending from the convex portion to an edge of the support portion over the entire circumference of the convex portion when viewed from the protruding direction of the convex portion. They are placed consecutively.

A power storage element according to one aspect of the present invention includes an electrode body formed by winding an electrode plate, a container accommodating the electrode body, and an auxiliary support disposed between an inner surface of the container and the electrode body. The electrode body has a flat part, and the auxiliary member includes a flat support part disposed on the side of the transverse direction of a cross section perpendicular to the winding axis direction of the electrode body. , a convex portion provided on the support portion and pressing the flat portion of the electrode body; and a convex portion connected to the support portion and located on a side in the longitudinal direction of the cross section perpendicular to the winding axis direction of the electrode body. and a regulating portion disposed, and only one convex portion is disposed at a position facing the flat portion in the support portion.

Further, the electricity storage element according to one aspect of the present invention includes an electrode body formed by winding an electrode plate, a container housing the electrode body, and an inner surface of the container and the electrode body. the electrode body has a flat portion; the auxiliary member includes a support portion disposed on a side in the lateral direction of a cross section perpendicular to the winding axis direction of the electrode body; a convex part provided on the support part and pressing the flat part of the electrode body; and a regulating portion, the convex portion having a recess forming a cavity inside the convex portion, and an embedded member may be embedded in the recess.

Further, the electricity storage element according to one aspect of the present invention includes an electrode body formed by winding an electrode plate, a container housing the electrode body, and an inner surface of the container and the electrode body. the auxiliary member is provided with a first support part disposed on one side in the direction of the winding axis of the electrode body; and the auxiliary member is provided on the first support part, and the auxiliary member It may also include a first protrusion inserted into the center, and a restriction part that restricts movement of the first support part in the longitudinal direction of a cross section perpendicular to the winding axis direction of the electrode body. .

According to this configuration, the first protrusion is inserted into the winding center of the electrode body (for example, the part forming the cavity into which the shaft of the winding device was inserted), so that the electrode body is moved to the winding center. pushed by the first protrusion in a direction outward from the section. Thereby, the frictional force between the inner surface of the container and the electrode body can be increased, and as a result, movement of the electrode body inside the container is suppressed. Further, since the first support portion having the first protrusion is regulated from moving in the longitudinal direction in the cross section of the electrode body, for example, the first protrusion and the inner surface of the winding center of the electrode body are regulated by the restriction portion. Damage to the electrode body due to rubbing against each other (misalignment) is suppressed.

Specifically, for example, in a flat wound electrode body, the flat part that tends to dent inward is pushed outward by the first protrusion, thereby increasing the frictional force between the electrode body and the inner surface of the container. . Further, since the auxiliary member has the regulating portion, movement of the first protruding portion in the longitudinal direction is regulated at the center of the winding of the electrode body, which has a flat shape similar to the outer shape. Therefore, even if the first protrusion is made shorter with respect to the winding center in the longitudinal direction, displacement of the first protrusion in the longitudinal direction is suppressed. In other words, the first protrusion is arranged in a manner that does not apply unnecessary stress to the electrode body. Therefore, the power storage element for this purpose is a highly reliable power storage element.

Further, in the electricity storage element according to one aspect of the present invention, the restriction portion may be connected to the first support portion and disposed on a side surface of the electrode body in the longitudinal direction.

According to this configuration, the displacement of the first protrusion in the longitudinal direction is suppressed by a simple configuration in which the regulating portion is disposed on the side surface of the electrode body in the longitudinal direction of the cross section.

Further, in the electricity storage element according to one aspect of the present invention, an electrode terminal is provided on one surface of the container, and the regulating portion is arranged between the electrode body and the electrode terminal of the container. It may be arranged between one surface and the opposite surface.

According to this configuration, the restricting part is arranged between the side surface of the electrode body and the inner surface of the container, which is a simple configuration, and the position of the first protrusion part in both directions parallel to the longitudinal direction of the cross section of the electrode body can be adjusted. Misalignment is suppressed.

Further, in the electricity storage element according to one aspect of the present invention, the first protrusion has a taper such that the width in the transverse direction of the cross section of the electrode body becomes narrower as it moves away from the first support part. , may also be used.

According to this configuration, since the first protrusion has a taper, the first protrusion can be smoothly inserted into the winding center, for example. In other words, while suppressing deformation (creating wrinkles) of the inner surface of the winding center by inserting the first protrusion into the center of the winding of the electrode body, the first projection can be inserted into the center of the electrode body more reliably. It can be inserted all the way inward. Furthermore, since the first protrusion is tapered so that the width (width in the lateral direction of the cross section of the electrode body) is narrowed, the flat part of the electrode body can be efficiently pushed outward.

Further, in the power storage element according to one aspect of the present invention, the first protrusion has a recess that forms a cavity inside the first protrusion, and an embedded member is embedded in the recess. You can also use it as

According to this configuration, for example, even if the auxiliary member is formed of a relatively thin sheet-like material, the buried member is placed in the recess of the first protrusion, so that the first protrusion is The hardness can be sufficient to push the electrode body outward from the center of the winding. In other words, according to the auxiliary member of this aspect, for example, by using a relatively thin sheet as the auxiliary member, it is possible to improve the effect of suppressing movement of the electrode body within the container while suppressing consumption of the internal volume of the container. can.

Further, in the electricity storage element according to one aspect of the present invention, the electrode body has a core material forming the winding center part of the electrode body, and the first protrusion part is inserted into the core material. It may be said that there is.

According to this configuration, for example, even if the electrode body is formed by winding the electrode plate around the core material, the first protrusion can be inserted into the space that the core material has. It can be used as the center of winding. That is, the auxiliary member can push the electrode body outward from the winding center by utilizing the hollow portion of the core material.

Further, in the electricity storage element according to one aspect of the present invention, the auxiliary member is further provided at a second support portion disposed on the other end surface of the electrode body in the winding axis direction, and at the second support portion, and a second protrusion inserted into the winding center of the electrode body, and the first support part and the second support part may be connected to the restriction part.

According to this configuration, the protruding portion is inserted into the center of the winding of the electrode body from both directions parallel to the winding axis direction. Therefore, it is possible to further increase the frictional force between the inner surface of the container and the electrode body, or to suppress movement of the electrode body in a well-balanced manner due to the frictional force. In addition, since the first support part and the second support part are connected to one regulating part, the structure is simple, and the longitudinal direction of the two protrusion parts (the first protrusion part and the second protrusion part) in the cross section of the electrode body can be easily adjusted. positional shift can be suppressed. That is, damage to the electrode body caused by displacement of the two protrusions in the longitudinal direction can be suppressed with a simple configuration.

Further, in the electricity storage element according to one aspect of the present invention, the electrode body has a flat part, the auxiliary member further has a third support part connected to the regulation part, and the third support part is connected to the third support part. Alternatively, a convex portion may be provided that presses the flat portion of the electrode body.

According to this configuration, the flat part of the electrode body that is pushed from the inside to the outside by the first protrusion can be pushed from the outside to the inside by the convex part of the third support part. In other words, the frictional force between the inner surface of the container and the electrode body can be further increased, and as a result, the movement of the electrode body within the container can be suppressed more reliably.

Further, in the power storage element according to one aspect of the present invention, the auxiliary member may be formed of a single sheet-like material.

According to this configuration, the auxiliary member can be manufactured by, for example, press molding or vacuum molding on a single resin sheet, and therefore mass production is easy. Further, the auxiliary member can also be realized by an insulating sheet that insulates the electrode body and the container. In other words, the auxiliary member can also function as an insulating sheet that insulates the electrode body and the container.

According to the present invention, there is provided a power storage element comprising an electrode body formed by winding an electrode plate and a container accommodating the electrode body, in which movement of the electrode body inside the container is suppressed. can be provided. That is, according to the present invention, a power storage element with improved reliability can be provided.

FIG. 1 is a perspective view showing the appearance of a power storage element according to an embodiment. It is a perspective view showing the constituent elements arranged in the container of the electricity storage element concerning an embodiment. FIG. 1 is a perspective view showing a general configuration of an electrode body according to an embodiment. FIG. 2 is a diagram showing a general configuration of an electrode body according to an embodiment when viewed from the direction of a winding axis. It is a perspective view showing the composition of the auxiliary member concerning an embodiment. FIG. 2 is a first partial cross-sectional view of a power storage element according to an embodiment. FIG. 3 is a second partial cross-sectional view of the power storage element according to the embodiment. It is a perspective view showing the structural relationship between the auxiliary member and the buried member according to the embodiment.

Hereinafter, a power storage element according to an embodiment of the present invention will be described with reference to the drawings. Note that each figure is a schematic diagram and is not necessarily strictly illustrated.

Moreover, the embodiment described below shows one specific example of the present invention. The shapes, materials, components, arrangement positions and connection forms of the components, order of manufacturing steps, etc. shown in the following embodiments are merely examples, and do not limit the present invention. Further, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the most significant concept will be described as arbitrary constituent elements.

First, a general description of the power storage element 10 according to the embodiment will be given using FIGS. 1 and 2.

FIG. 1 is a perspective view showing the appearance of a power storage element 10 according to an embodiment. FIG. 2 is a perspective view showing the components arranged in the container 100 of the power storage element 10 according to the embodiment. Specifically, FIG. 2 is a perspective view showing the power storage element 10 with the lid 110 and main body 111 of the container 100 separated and the auxiliary member 50 removed from the electrode body 400.

The power 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 may be used in a mobile vehicle such as a vehicle such as an electric vehicle (EV), a plug-in hybrid electric vehicle (PHEV), or a hybrid electric vehicle (HEV), a motorcycle, a watercraft, a snowmobile, an agricultural machine, or a construction machine. It is used as a battery for driving a car or starting an engine. Note that the power storage element 10 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or a capacitor. Furthermore, the power storage element 10 may be a primary battery that allows the user to use the stored electricity without charging it.

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

Note that although a liquid such as an electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100 of the power storage element 10, illustration of the liquid is omitted. Further, the type of electrolytic solution sealed in container 100 is not particularly limited as long as it does not impair the performance of power storage element 10, and various types can be selected.

The container 100 includes a main body 111 having a rectangular cylindrical shape and a bottom, and a lid 110 that is a plate-like member that closes an opening of the main body 111. Further, the container 100 has a structure in which the interior is sealed by welding the lid 110 and the main body 111 after housing the electrode body 400 and the like therein. Note that the material of the lid 110 and the main body 111 is not particularly limited, but is preferably a weldable metal such as stainless steel, aluminum, or an aluminum alloy.

The electrode body 400 is a member 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 using FIG. 3 and the like.

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

Current collector 120 is a member that is electrically connected to negative electrode terminal 200 and the negative electrode of electrode body 400 . The current collector 130 is a member that is electrically connected to the positive electrode terminal 300 and the positive electrode of the electrode body 400.

Specifically, current collectors 120 and 130 are fixed to lid 110. Further, the current collector 120 is joined to the negative electrode side end of the electrode body 400, and the current collector 130 is joined to the positive electrode side end of the electrode body 400. The electrode body 400 is held inside the container 100 in a suspended state from the lid body 110 by the current collectors 120 and 130. In this embodiment, each of current collectors 120 and 130 is bonded to electrode body 400 by, for example, ultrasonic bonding. Note that the method of joining the current collectors 120 and 130 and the electrode body 400 is not particularly limited, and the current collectors 120 and 130 and the electrode body 400 may be joined by resistance welding, clinch caulking, or the like.

Further, as shown in FIG. 2, the power storage element 10 according to the present embodiment further includes an auxiliary member 50. The auxiliary member 50 is a member attached to the electrode body 400 to which the current collectors 120 and 130 are joined. The auxiliary member 50 is provided with a first support part 61 disposed on one side in the direction of the winding axis of the electrode body 400 and the first support part 61, and is inserted into the winding center part 401 of the electrode body 400. It has a first protrusion 51 which is shaped like a first protrusion. The auxiliary member 50 pushes the electrode body 400 outward from the winding center 401 to increase the frictional force (static frictional force) between the inner surface 111a of the container 100 and the electrode body 400. It is a member. Details of the auxiliary member 50 will be described later using FIGS. 5 and 6.

Next, the configuration of the electrode body 400 included in the power storage element 10 configured as described above will be described using FIGS. 3 and 4. FIG. 3 is a perspective view showing a general configuration of an electrode body 400 according to an embodiment. In addition, in FIG. 3, elements such as stacked and wound electrode plates are partially expanded and illustrated. Further, in FIG. 3, a dashed-dotted line marked with the symbol W represents the winding axis of the electrode body 400. The winding axis W is a virtual axis serving as a central axis when winding the electrode plate, etc., and in this embodiment, is a straight line parallel to the X-axis passing through the center of the electrode body 400. That is, in this embodiment, "the direction of the winding axis W" is synonymous with the "X-axis direction". FIG. 4 is a diagram showing an outline of the configuration of the electrode body 400 according to the embodiment when viewed from the direction of the winding axis W. As shown in FIG.

The electrode body 400 is an example of an electrode body formed by winding an electrode plate. In this embodiment, as shown in FIG. 3, the electrode body 400 is formed by laminating a separator 450, a negative electrode plate 420, a separator 430, and a positive electrode plate 410 in this order and winding them. has been done. Further, as shown in FIG. 4, the electrode body 400 has a flat shape in a direction perpendicular to the winding axis W (Y-axis direction in this embodiment). In other words, the electrode body 400 has an oval shape as a whole when viewed from the direction of the winding axis W, the straight line portion of the oval shape is a flat shape, and the curved portion of the oval shape is a curved shape. Become. Therefore, the electrode body 400 has a pair of opposing curved portions 407 (portions facing each other in the Z-axis direction with the winding axis W in between) and a flat portion 405 that is a portion between the pair of curved portions 407. are doing.

In the present embodiment, the positive electrode plate 410 includes a composite material layer forming portion 414 in which a positive electrode composite material layer containing a positive electrode active material is formed on the surface of a long belt-shaped metal foil made of aluminum (positive electrode base material layer 411). including. The negative electrode plate 420 includes a composite material layer forming portion 424 in which a negative electrode composite material layer containing a negative electrode active material is formed on the surface of a long strip-shaped metal foil (negative electrode base material layer 421) made of copper. As the positive electrode active material and the negative electrode active material used in the electrode body 400, any known material can be used as appropriate, as long as it does not impair the performance of the power storage element 10.

Further, in this embodiment, separators 430 and 450 have a microporous sheet made of resin as a base material.

In the electrode body 400 configured in this way, more specifically, the positive electrode plate 410 and the negative electrode plate 420 are wound with a separator 430 or 450 interposed therebetween so as to be offset from each other in the direction of the winding axis W. The positive electrode plate 410 and the negative electrode plate 420 each have a composite material layer non-formed portion, which is a portion of the base material layer where the composite material layer is not formed, at the ends in the respective shifted directions.

Specifically, the positive electrode plate 410 has a composite material layer non-formed portion 411a in which the positive electrode composite material layer is not formed at one end in the direction of the winding axis W (the end on the negative side in the X-axis direction in FIG. 3). have. Further, the negative electrode plate 420 has a composite material layer non-formed portion 421a in which the negative electrode composite material layer is not formed at the other end in the direction of the winding axis W (the end on the positive side in the X-axis direction in FIG. 3). ing.

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

As shown in FIG. 4, the electrode body 400 has an oval shape that is flat in the Y-axis direction when viewed from the direction of the winding axis W, and the winding center portion 401 is also flat in the Y-axis direction. It is formed into an oval shape.

Here, the winding center portion 401 is formed so that the axis is rotated when winding an element constituting the electrode body 400 (hereinafter also referred to as "electrode body element"), such as the negative electrode plate 420, with a winding device. This is the part that forms the cavity in which it was inserted. That is, the winding center portion 401 is a portion that forms a space that exists in the center of the electrode body 400 shown in FIG. 4, and is a portion that forms the innermost periphery of the electrode body 400 in this embodiment. More specifically, in this embodiment, the electrode body 400 has a core material 480, and the core material 480 forms the winding center portion 401.

The electrode body 400 having the above configuration is formed by winding the electrode body elements around the core material 480 and then compressing them in the Y-axis direction. Note that the core material 480 is a member made of resin such as polypropylene or polyethylene.

Note that the core material 480 may be a member formed by winding a resin sheet, or may be a member formed into a flat shape. Moreover, the core material 480 may be a member formed integrally, or may be formed from a plurality of members. Further, the material of the core material 480 is not particularly limited. For example, when placing the separator at the position closest to the core material 480 and when dropping the potential of either the positive electrode or the negative electrode to the core material 480, a conductive material may be used as the material of the core material 480. Good too. Further, the core material 480 is not an essential element for the electrode body 400, and the electrode body 400 may be formed by winding electrode body elements such as the separator 450 and the negative electrode plate 420 without the core material 480. . In this case, the winding center portion 401 is formed by, for example, a separator 430.

In this embodiment, the auxiliary member 50 is attached to the electrode body 400 configured as described above after the current collectors 120 and 130 are joined by ultrasonic bonding or the like. The electrode body 400 with the auxiliary member 50 attached is housed in the main body 111.

Next, the configuration of the auxiliary member 50 according to this embodiment will be explained using FIGS. 5 to 7. FIG. 5 is a perspective view showing the configuration of the auxiliary member 50 according to the embodiment. In addition, in FIG. 5, the auxiliary member 50 is illustrated with elements such as the first support portion 61 connected to the regulating portion 70 expanded so that the configuration of the auxiliary member 50 can be easily recognized. That is, FIG. 5 is a developed view of the auxiliary member 50. Further, in FIG. 5, the electrode body 400 is simply illustrated in order to show the structural relationship between each element included in the auxiliary member 50 and the electrode body 400.

FIG. 6 is a first partial cross-sectional view of power storage element 10 according to the embodiment, and FIG. 7 is a second partial cross-sectional view of power storage element 10 according to the embodiment. In addition, in FIG. 6, a part of the cross section of the power storage element 10 in the XZ plane passing through the VI-VI line shown in FIG. 2 is illustrated in a simplified manner. In FIG. 7, a part of the cross section of the power storage element 10 in the XY plane passing through the line VII-VII shown in FIG. 2 is illustrated in a simplified manner. Further, in FIGS. 6 and 7, illustration of the current collector 120 and the like is omitted in order to show the structural relationship between the first protrusion 51 of the auxiliary member 50 and the electrode body 400.

As shown in FIGS. 5 to 7, the power storage element 10 according to the present embodiment includes an electrode body 400 formed by winding electrode plates (410, 420), and a container 100 that houses the electrode body 400. , and an auxiliary member 50 disposed between the inner surface of the container 100 and the electrode body 400.

The auxiliary member 50 is provided at a first support portion 61 disposed on one side in the direction of the winding axis W of the electrode body 400 and at the first support portion 61 , and is provided at the winding center portion 401 of the electrode body 400 . The inserted first protruding portion 51 and the first supporting portion 61 are arranged in a longitudinal direction (in this embodiment, a cross section (hereinafter referred to as a “longitudinal cross section”) perpendicular to the direction of the winding axis W of the electrode body 400. and a regulating portion 70 that regulates movement in the Z-axis direction).

As described above, in the present embodiment, the first protruding portion 51 of the auxiliary member 50 is inserted into the winding center portion 401 of the electrode body 400, so that the electrode body 400, for example, as shown in FIG. It is pushed by the first protrusion 51 in the direction outward from the winding center 401 . This increases the frictional force between the inner surface 111a of the main body 111 of the container 100 and the electrode body 400, and as a result, movement of the electrode body 400 inside the container 100 is suppressed. Specifically, for example, a flat portion 405 (see FIG. 4) that tends to be recessed inward in the flat wound electrode body 400 is pushed outward by the first protrusion 51, thereby causing the electrode body 400 and the container to The frictional force between the inner surface 111a of 100 and the inner surface 111a of 100 is increased.

Furthermore, movement of the first support part 61 having the first protrusion part 51 in the longitudinal direction (Z-axis direction) in the longitudinal section of the electrode body 400 is restricted by the restriction part 70 . Therefore, damage to the electrode body 400 due to, for example, displacement of the first protruding portion 51 in the longitudinal direction (Z-axis direction) with respect to the winding center portion 401 is suppressed. In other words, since the auxiliary member 50 has the regulating part 70, the first protrusion in the longitudinal direction (Z-axis direction) is caused in the winding center part 401 (see FIG. 4), which has a flat shape similar to the outer shape of the electrode body 400. Movement of the portion 51 is restricted.

Therefore, as shown in FIG. 6, for example, even if the width of the first protruding part 51 is made shorter than the winding center part 401 in the Z-axis direction, the first protruding part 51 and the electrode body 400 The possibility of the two rubbing against each other in the Z-axis direction is reduced.

Here, even if the auxiliary member 50 does not have the regulating part 70, the width of the first protruding part 51 in the Z-axis direction is made approximately the same as the width of the winding center part 401 in the Z-axis direction. Thus, it is possible to suppress movement of the first protrusion 51 in the Z-axis direction without depending on the restriction part 70. In other words, by bringing both ends of the first protrusion 51 in the Z-axis direction into contact with the inner surface of the winding center portion 401 in the Z-axis direction, it is possible to suppress movement of the first protrusion 51 in the Z-axis direction. It is. However, in this case, when the first protrusion 51 attempts to move in the Z-axis direction relative to the electrode body 400, the first protrusion 51 necessarily moves the inner surface of the winding center portion 401 in the Z-axis direction outward. It will be in a state of being pressed. Furthermore, as in the present embodiment, when the first protruding portion 51 is elongated in the Z-axis direction and flat (thin) in the Y-axis direction, like the winding center portion 401, The contact area between the first protrusion 51 and the inner surface of the winding center portion 401 in the Z-axis direction is relatively small. Therefore, when the first protruding part 51 tries to move in the Z-axis direction, the pressure (pressing force per unit area) exerted by the first protruding part 51 on the inner surface of the winding center part 401 becomes relatively large. As a result, for example, the end of the winding center portion 401 in the direction of the winding axis W may be pushed out in the Z-axis direction, and there is a possibility that elements such as the negative electrode plate 420 outside the end may be damaged. .

In this regard, the auxiliary member 50 according to the present embodiment includes a restricting portion 70 that restricts movement of the first protruding portion 51 in the Z-axis direction with respect to the electrode body 400. Therefore, even if the width of the first protruding portion 51 in the Z-axis direction is approximately the same as the width of the winding center portion 401 in the Z-axis direction, the first protruding portion 51 may A situation in which it is pushed out in the Z-axis direction is unlikely to occur.

Further, in this embodiment, the relationship between the first protrusion 51 and the winding center portion 401 has a more advantageous structure. Specifically, the first protrusion 51 according to the present embodiment is arranged away from the inner surface of the winding center portion 401 in the Z-axis direction, as shown in FIG. In other words, the first protrusion 51 is unlikely to act on the inner surface of the winding center portion 401 in the Z-axis direction. Further, as shown in FIG. 6, for example, the auxiliary member 50 has the restriction portion 70, thereby restricting movement of the first support portion 61 having the first protrusion portion 51 in the Z-axis direction.

As explained above, according to the auxiliary member 50 according to the present embodiment, the displacement of the first protrusion 51 in the Z-axis direction can be suppressed without depending on the inner surface of the winding center portion 401 in the Z-axis direction. can do. That is, the first protrusion 51 is arranged in a manner that does not apply unnecessary stress to the electrode body 400. Therefore, the power storage element 10 according to the present embodiment is a highly reliable power storage element 10.

In this embodiment, as shown in FIG. 6, for example, when viewed from the direction perpendicular to the winding axis W, the first protrusion 51 disposed on the negative electrode side is in contact with the composite material layer forming part 424. It has an overlapping length (a length that reaches the composite material layer forming section 424). In other words, the first protruding portion 51 has a length that exceeds the composite layer non-forming portion 421a, which is the exposed portion of the negative electrode base material layer 421. In other words, the first protrusion 51 is inserted to a relatively deep position in the winding center 401, and thereby the electrode body 400 is pushed outward from the winding center 401. The effectiveness of suppressing movement of the body 400 is improved.

Further, in the present embodiment, the regulating portion 70 is connected to the first supporting portion 61 and is disposed on a side surface in the longitudinal direction (Z-axis direction) in the longitudinal section of the electrode body 400. That is, for example, the movement of the first protrusion 51 in the longitudinal direction is restricted by the restriction portion 70 coming into contact with or being in contact with the side surface of the electrode body 400 . In this way, with a simple configuration in which the regulating portion 70 is arranged on the side surface of the longitudinal section of the electrode body 400 in the longitudinal direction, it is possible to suppress the displacement of the first protruding portion 51 in the longitudinal direction.

Note that in the present embodiment, the regulating section 70 and the first supporting section 61 are directly connected, but between the regulating section 70 and the first supporting section 61, for example, the regulating section 70 and the first supporting section 61 are connected to each other. A connecting portion that is a separate member from the supporting portion 61 may be interposed. In other words, the regulating portion 70 and the first support portion 61 may be indirectly connected. Even in this case, movement of the first support part 61 and the first protrusion part 51 included in the first support part 61 is restricted by restricting the movement of the restriction part 70.

Further, in the present embodiment, electrode terminals (200, 300) are provided on one surface of the container 100 (the upper surface of the lid 110 in this embodiment), and the regulating portion 70 is provided with the As shown, it is arranged between the electrode body 400 and a surface of the container 100 that faces the one surface (in this embodiment, the bottom surface 111b of the container 100).

According to this configuration, with a simple configuration in which the regulating portion 70 is disposed between the side surface of the electrode body 400 and the inner surface (bottom surface 111b) of the container 100, the first protrusion portion 51 can be Bidirectional positional displacement parallel to the longitudinal direction of the surface is suppressed.

Further, in the present embodiment, the first protrusion 51 has a width in the transverse direction (in the present embodiment, the Y-axis direction) of the longitudinal section of the electrode body 400, as shown in FIGS. 5 and 7, for example. , has a taper 51a that becomes narrower as it moves away from the first support portion 61.

Since the first protrusion 51 has the taper 51a, the first protrusion 51 can be smoothly inserted into the winding center 401, for example. In this case, the first protrusion 51 can be inserted into the winding center 401 of the electrode body 400 while suppressing deformation (creating wrinkles) of the inner surface of the winding center 401. , the electrode body 400 can be inserted more reliably into the interior. Further, since the taper 51a is formed so that the width (width in the Y-axis direction) is narrow, the flat portion 405 of the electrode body 400 can be efficiently pushed outward.

Note that in the present embodiment, the taper 51a is formed continuously in the first protrusion 51 from the tip in the X-axis direction to the root (connection part with the first support part 61); The taper 51a may be formed only in a portion from the tip to the root. For example, in the first protrusion 51, both surfaces in the Y-axis direction from the tip to a predetermined position may be formed parallel to the X-axis direction, and a taper 51a may be formed from the predetermined position to the base. Even in this case, the relatively thin tip of the first protrusion 51 ensures ease of insertion into the winding center 401. Further, since the first protruding portion 51 is formed with a portion that gradually becomes thicker due to the taper 51a, an effect is achieved in that the flat portion 405 of the electrode body 400 can be efficiently pushed outward.

Further, in this embodiment, the electrode body 400 has a core material 480 that forms the winding center portion 401 of the electrode body 400, and the first protrusion portion 51 is inserted into the core material 480.

As described above, the core material 480 of the wound electrode body 400 is formed of a flexible member such as a resin sheet. In addition, the core material 480 has a space (cavity) that communicates from at least one end in the direction of the winding axis to the inside in order to pass the shaft of the winding device therethrough. That is, the winding center portion 401 into which the first protruding portion 51 can be inserted is formed of a flexible core material 480.

Therefore, the space that the core material 480 has can be used as the winding center 401 into which the first protrusion 51 is inserted, thereby pushing the electrode body 400 outward from the winding center 401. be able to.

6 and 7, the configuration of the negative electrode side (positive side in the X-axis direction) of the auxiliary member 50 was illustrated and explained, but the auxiliary member 50 according to the present embodiment is, for example, shown in FIG. As shown in , the positive electrode side (minus side in the X-axis direction) also has a protrusion and the like.

Specifically, in the power storage element 10 according to the present embodiment, the auxiliary member 50 further includes a second electrode disposed on the other end surface of the electrode body 400 in the direction of the winding axis W (the end surface on the negative side in the X-axis direction). It has two support parts 62 and a second protrusion part 52 provided on the second support part 62 and inserted into the winding center part 401 of the electrode body 400. The first support part 61 and the second support part 62 are connected to the restriction part 70. In this embodiment, the first support part 61 is connected to one end of the regulating part 70 in the longitudinal direction (X-axis direction), and the second support part 62 is connected to the other end.

According to this configuration, the protrusions (first protrusion 51 and second protrusion 52) are inserted into the winding center 401 of the electrode body 400 from both directions parallel to the winding axis W. Therefore, it is possible to further increase the frictional force between the inner surface 111a of the container 100 and the electrode body 400, or to suppress movement of the electrode body 400 in a well-balanced manner due to the frictional force.

Moreover, since the first support part 61 and the second support part 62 are connected to one regulating part 70, the electrodes of the two protrusions (first protrusion 51 and second protrusion 52) can be easily connected to each other with a simple configuration. Displacement in the longitudinal direction (Z-axis direction) in the longitudinal section of the body 400 can be suppressed. That is, damage to the electrode body 400 caused by displacement of the two protrusions (first protrusion 51 and second protrusion 52) in the longitudinal direction can be suppressed with a simple configuration.

Further, in the present embodiment, the second protruding portion 52 has a taper 52a such that the width in the transverse direction of the longitudinal section of the electrode body 400 becomes narrower as the distance from the second support portion 62 increases. Thereby, effects such as being able to smoothly insert the second protruding portion 52 into the winding center portion 401 and being able to efficiently push the flat portion 405 of the electrode body 400 outward are achieved. .

Further, in this embodiment, the electrode body 400 has a flat portion 405, as shown in FIG. 4, for example, and the auxiliary member 50 further has a flat portion 405, as shown in FIG. It has three support parts 63. The third support portion 63 is provided with a convex portion 81 that presses the flat portion 405 of the electrode body 400 .

According to this configuration, for example, the flat part 405 of the electrode body 400 that is pushed from the inside to the outside by the first protrusion 51 is pushed from the outside to the inside by the convex part 81 of the third support part 63. (See FIGS. 5 and 7). In other words, the frictional force between the inner surface 111a of the container 100 and the electrode body 400 can be further increased, and as a result, the movement of the electrode body 400 within the container 100 can be suppressed more reliably.

In this embodiment, the auxiliary member 50 includes a pair of third support parts 63 that are arranged to face each other in the transverse direction (Y-axis direction) of the longitudinal section of the electrode body 400. Therefore, for example, the flat portion 405 of the electrode body 400 can be supported by the pair of convex portions 81 from both sides in the Y-axis direction. This is advantageous from the viewpoint of suppressing movement of the electrode body 400.

In addition, in this embodiment, the flat portion 405 can be expressed as a portion between a pair of curved portions 407, and can also be expressed as a portion between the pair of curved portions 407, for example, when the electrode body 400 is seen through from the lateral direction (Y-axis direction) of the longitudinal section. , a portion where the winding center portion 401 is present.

Further, in this embodiment, the auxiliary member 50 is formed of a single sheet-like material. For example, the auxiliary member 50 including three-dimensional elements such as the first protrusion 51 can be produced by performing pressure molding or vacuum forming on a sheet made of a resin such as polypropylene or polyethylene.

In this way, the auxiliary member 50 can be manufactured, for example, by processing such as press molding on a single resin sheet, and therefore mass production is easy. Further, the auxiliary member 50 can also be realized by an insulating sheet that insulates the electrode body 400 and the container 100. In other words, the auxiliary member 50 can also function as an insulating sheet that insulates the electrode body 400 and the container 100. In other words, the auxiliary member 50 according to the present embodiment is suitable as a member for suppressing movement of the electrode body 400 in the power storage element 10 having the container 100 that has not been lowered to the positive or negative potential of the electrode body 400.

Note that when the auxiliary member 50 is formed of a single sheet-like material, a cavity is formed inside the first protrusion 51, as shown in FIGS. 2, 6, and 7. That is, the first protrusion 51 has a recess 71 that forms a cavity. The recess 71 may be used to improve the effect of the first protrusion 51 on suppressing movement of the electrode body 400.

FIG. 8 is a perspective view showing the structural relationship between the auxiliary member 50 and the buried member 90 according to the embodiment. For example, as shown in FIG. 8, the first protrusion 51 has a recess 71 that forms a cavity inside the first protrusion 51, and the buried member 90 may be embedded in the recess 71. . The buried member 90 is, for example, a solid or hollow member made of resin, and when inserted into the recess 71, both side surfaces in the Y-axis direction have a shape and size that follow the inner surfaces on both sides of the recess 71 in the Y-axis direction. It is molded into.

In this way, by disposing the embedded member 90 inside the recess 71 of the first protrusion 51, even if the auxiliary member 50 is formed of a relatively thin sheet-like material, the first protrusion The hardness of the portion 51 can be made sufficiently hard to push the electrode body 400 outward.

In other words, by forming the auxiliary member 50 from a relatively thin sheet-like material, the consumption of the internal volume of the container 100 by the auxiliary member 50 is suppressed, and the movement of the electrode body 400 within the container 100 is suppressed. The suppression effect can be improved.

Although FIG. 8 shows a configuration in which the embedded member 90 is arranged in the recess 71 of the first protrusion 51, the embedded member 90 may be arranged in the recess of the second protrusion 52. Thereby, effects such as improvement in the hardness of the second protrusion 52 can be obtained.

Further, in this embodiment, the convex portion 81 provided on the third support portion 63 of the auxiliary member 50 is a portion formed by press molding etc., like the first protrusion portion 51, and is opposite to the protrusion direction. A recess is formed on the side (see, for example, FIG. 7). Therefore, an embedded member may be placed in this recess. Thereby, the convex portion 81 can be made hard, and as a result, the effect of suppressing movement of the electrode body 400 due to the convex portion 81 pressing the electrode body 400 is improved.

(Other embodiments)
Above, the electricity storage element and the manufacturing method thereof according to the present invention have been described based on the embodiments. However, the present invention is not limited to the above embodiments. Unless departing from the spirit of the present invention, various modifications that can be thought of by those skilled in the art to the above-described embodiments, or forms constructed by combining a plurality of the above-described components are within the scope of the present invention. include.

For example, the auxiliary member 50 does not need to be formed from a single sheet of material. For example, a three-dimensional member such as the first protruding portion 51 that is separate from the base member is adhered to a sheet-like base member that forms the flat plate-like portions such as the regulating portion 70 and the first supporting portion 61. Alternatively, the auxiliary member 50 may be formed by welding. In this case, for example, it is possible to manufacture the first protrusion 51 as a solid member, and thereby it is possible to manufacture the first protrusion 51 as a relatively hard member.

Furthermore, for example, the shape of the container 100 included in the power storage element 10 does not have to be a rectangular parallelepiped as shown in FIG. 1 . For example, the auxiliary member 50 is disposed in a power storage element 10 that houses a wound electrode body 400 and includes a container 100 that has an oval or oval shape when viewed from the direction of the winding axis W. may be done.

In other words, even if the shape of the container 100 is not a rectangular parallelepiped, by disposing the regulating part 70 on the side surface of the electrode body 400 in the direction perpendicular to the winding axis W, the regulating part 70 can at least 400, movement is restricted. As a result, movement of the first protrusion 51 included in the first support part 61 connected to the restriction part 70 is restricted. Therefore, as described in the above embodiment, it is possible to suppress the movement of the electrode assembly 400 within the container 100 without applying unnecessary stress to the electrode assembly 400.

Further, in the present embodiment, power storage element 10 includes only one electrode body 400, but power storage element 10 may include two or more electrode bodies 400. For example, when power storage element 10 includes two electrode bodies 400, current collector 120 may have four legs joined to two electrode bodies 400. Further, in this case, the auxiliary member 50 may have the first protruding portion 51 at a position corresponding to the winding center portion 401 of each of the two electrode bodies 400 on the first supporting portion 61. Even in this case, the effect of suppressing movement within the container 100 can be obtained for each of the two electrode bodies 400.

Further, the present invention can be realized not only as the electricity storage element described above, but also as an auxiliary member included in the electricity storage element. Further, the present invention can be realized as a power storage device including a plurality of the power storage elements.

The present invention can be applied to power storage elements such as lithium ion secondary batteries.

10 Energy storage element 50 Auxiliary member 51 First protruding part 51a, 52a Taper 52 Second protruding part 61 First supporting part 62 Second supporting part 63 Third supporting part 70 Regulating part 71 Recessed part 81 Convex part 90 Buried member 100 Container 111a Inner surface 111b Bottom surface 200 Negative electrode terminal 300 Positive electrode terminal 400 Electrode body 401 Winding center portion 405 Flat portion 410 Positive electrode plate 420 Negative electrode plate 480 Core material

Claims (7)

an electrode body formed by winding an electrode plate;
a container containing the electrode body;
an auxiliary member disposed between the inner surface of the container and the electrode body,
The electrode body has a flat part,
The auxiliary member is
a flat support part disposed on the side in the short direction of a cross section perpendicular to the winding axis direction of the electrode body;
A convex portion provided on the support portion to press the flat portion of the electrode body, wherein the flat portion of the support portion is provided around the entire circumference of the convex portion when viewed from the protruding direction of the convex portion. A convex portion arranged in a position,
a regulating part connected to the supporting part and disposed on a side in the longitudinal direction of the cross section perpendicular to the winding axis direction of the electrode body,
The flat portion of the support portion is provided continuously from the convex portion to an edge of the support portion around the entire circumference of the convex portion when viewed from the protruding direction of the convex portion,
When viewed from a direction perpendicular to the protrusion direction of the protrusion, the protrusion protrudes to a position overlapping with the electrode body,
The flat part is depressed in the protruding direction by being pressed by the convex part,
The electrode body includes curved portions on both sides of the flat portion in the longitudinal direction,
A convex portion protruding toward the curved portion is provided at a position of the supporting portion facing the curved portion in the transverse direction and a position of the regulating portion facing the curved portion in the longitudinal direction. not placed,
Energy storage element. The auxiliary member has a pair of support parts including the support part, the pair of support parts being disposed at positions sandwiching the electrode body in the lateral direction,
The convex portion is provided on each of the pair of support portions,
The electricity storage element according to claim 1. The pair of convex portions are arranged at positions overlapping each other when viewed from the transverse direction,
The electricity storage element according to claim 2. The protrusion has a recess that forms a cavity inside the protrusion.
The electricity storage element according to any one of claims 1 to 3. An embedded member is embedded in the recess, and in a direction from the electrode body toward the inner surface of the container facing the support portion, the electrode body, the support portion, the embedded member, and the inner surface of the container are line up in order,
The electricity storage element according to claim 4. an electrode body formed by winding an electrode plate;
a container containing the electrode body;
an auxiliary member disposed between the inner surface of the container and the electrode body,
The electrode body has a flat part,
The auxiliary member is
a flat support part disposed on the side in the short direction of a cross section perpendicular to the winding axis direction of the electrode body;
a convex portion provided on the support portion and pressing the flat portion of the electrode body;
a regulating part connected to the supporting part and disposed on a side in the longitudinal direction of the cross section perpendicular to the winding axis direction of the electrode body,
Only one convex portion is disposed in the support portion at a position facing the flat portion,
When viewed from a direction perpendicular to the direction in which the protrusion protrudes, the protrusion protrudes to a position overlapping with the electrode body,
The flat part is depressed in the protruding direction by being pressed by the convex part,
The electrode body includes curved portions on both sides of the flat portion in the longitudinal direction,
A convex portion protruding toward the curved portion is provided at a position of the supporting portion facing the curved portion in the transverse direction and a position of the regulating portion facing the curved portion in the longitudinal direction. not placed,
Energy storage element. an electrode body formed by winding an electrode plate;
a container containing the electrode body;
an auxiliary member disposed between the inner surface of the container and the electrode body,
The electrode body has a flat part,
The auxiliary member is
a flat support part disposed on the side in the short direction of a cross section perpendicular to the winding axis direction of the electrode body;
A convex portion provided on the support portion to press the flat portion of the electrode body, wherein the flat portion of the support portion is provided around the entire circumference of the convex portion when viewed from the protruding direction of the convex portion. A convex portion arranged in a position,
a regulating part connected to the supporting part and disposed on a side in the longitudinal direction of the cross section perpendicular to the winding axis direction of the electrode body,
When viewed from a direction perpendicular to the protrusion direction of the protrusion, the protrusion protrudes to a position overlapping with the electrode body,
The flat part is depressed in the protruding direction by being pressed by the convex part,
The electrode body includes curved portions on both sides of the flat portion in the longitudinal direction,
A convex portion protruding toward the curved portion is provided at a position of the supporting portion facing the curved portion in the transverse direction and a position of the regulating portion facing the curved portion in the longitudinal direction. not placed,
Energy storage element.

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