JP7070596B2 - Power storage element - Google Patents

Description

The present invention relates to an electrode body formed by winding an electrode plate and a power storage element including a container for accommodating the electrode body.

The electrode body included in the power storage element is formed by winding, for example, those arranged in layers so that the separator is sandwiched between the positive electrode plate and the negative electrode plate. A technique for improving the resistance to impact and the like of a power storage element provided with such a winding type electrode body is disclosed. For example, in the power storage element described in Patent Document 1, the resistance to impact and the like is improved by the reinforcing member extending in the arrangement direction of the pair of current collectors and protruding from the pair of current collectors.

Japanese Patent Application Laid-Open No. 2015-162387

When a member for improving impact resistance or vibration resistance (for example, referred to as "auxiliary member") is arranged in the container as in the above-mentioned conventional technique, the auxiliary member is directly attached to the electrode body, for example. It is preferable that the electrode body is arranged in contact with the electrode body so as to act. However, this is disadvantageous from the viewpoint of avoiding damage to the electrode body by, for example, an auxiliary member. That is, how to arrange the auxiliary member in the container of the power storage element is not an easy problem because it has a balance with the effect of improving the resistance to vibration and the like.

The present invention has been made by the inventor of the present application paying new attention to the above-mentioned problems, and is a power storage element including an electrode body formed by winding an electrode body and a container for accommodating the electrode body. It is an object of the present invention to provide a highly reliable power storage element.

In order to achieve the above object, the power storage element according to one aspect of the present invention includes an electrode body formed by winding an electrode body, a container for accommodating the electrode body, an inner surface of the container, and the electrode body. The electrode body has a flat portion, and the auxiliary member is arranged on the lateral side of the cross section orthogonal to the winding axis direction of the electrode body. A support portion, a convex portion provided on the support portion and pressing the flat portion of the electrode body, and a longitudinal direction of the cross section connected to the support portion and orthogonal to the winding axis direction of the electrode body. The convex portion has a concave portion forming a cavity inside the convex portion, and an embedded member is embedded in the concave portion.

Further, the power storage element according to one aspect of the present invention is arranged between the electrode body formed by winding the electrode plate, the container accommodating the electrode body, the inner surface of the container, and the electrode body. The auxiliary member is provided with a first support portion arranged on one side in the winding axis direction of the electrode body and a first support portion provided on the first support portion, and the winding of the electrode body is provided. It may be provided with a first protruding portion inserted into the central portion and a regulating portion for restricting the movement of the first support portion in the longitudinal direction of the cross section orthogonal 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 portion forming the cavity into which the shaft of the winding device is inserted), so that the electrode body is the winding center. It is pushed by the first protrusion in the outward direction from the portion. As a result, the frictional force between the inner surface of the container and the electrode body can be increased, and as a result, the movement of the electrode body inside the container is suppressed. Further, since the first support portion having the first protrusion is restricted from moving in the longitudinal direction in the cross section of the electrode body by the regulation portion, for example, the first protrusion portion and the inner surface of the winding center portion of the electrode body Damage to the electrode body due to rubbing against each other (misalignment) is suppressed.

Specifically, for example, in a flat winding type electrode body, a flat surface that tends to be dented inward is extruded outward by the first protrusion, whereby the frictional force between the electrode body and the inner surface of the container is increased. .. Further, since the auxiliary member has the regulating portion, the movement of the first protruding portion in the longitudinal direction is restricted in the winding center portion of the electrode body having the same flat shape as the outer shape. Therefore, even when the first protrusion is shortened with respect to the winding center in the longitudinal direction, the positional deviation of the first protrusion in the longitudinal direction is suppressed. That is, the first protruding portion is arranged in a state where unnecessary stress is not applied to the electrode body. Therefore, the power storage element for this purpose is a highly reliable power storage element.

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

According to this configuration, the restricting portion is arranged on the side surface of the electrode body in the longitudinal direction of the cross section, and the displacement of the first protruding portion in the longitudinal direction is suppressed.

Further, in the power storage element according to one aspect of the present invention, an electrode terminal is provided on one surface of the container, and the restricting unit is provided with the electrode body and the electrode terminal of the container. It may be arranged between the surfaces facing one surface.

According to this configuration, the regulating portion is simply arranged between the side surface of the electrode body and the inner surface of the container, and the position of the first protruding portion in both directions parallel to the longitudinal direction of the cross section of the electrode body. The deviation is suppressed.

Further, in the power storage element according to one aspect of the present invention, the first protruding portion has a taper so that the width of the electrode body in the lateral direction becomes narrower as the distance from the first support portion increases. , May be.

According to this configuration, since the first protruding portion has a taper, for example, the first protruding portion can be smoothly inserted into the winding center portion. That is, by inserting the first protruding portion into the winding center portion of the electrode body, the deformation (creation of wrinkles) of the inner surface of the winding center portion is suppressed, and the first protruding portion is more reliably formed on the electrode body. It can be inserted all the way in. Further, since the taper is formed in the first protruding portion so that the lateral width (width in the lateral direction of the cross section of the electrode body) becomes narrow, the flat portion 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 protruding portion has a recess forming an internal cavity of the first protruding portion, and an embedded member is embedded in the recess. May be.

According to this configuration, for example, even when the auxiliary member is made of a relatively thin sheet-like material, the embedded member is arranged in the recess of the first protrusion so that the first protrusion can be formed. The hardness can be made sufficient to push the electrode body outward from the winding center. That is, according to the auxiliary member of this embodiment, for example, by using a relatively thin sheet as the auxiliary member, it is possible to improve the effect of suppressing the movement of the electrode body in the container while suppressing the consumption of the internal volume of the container. can.

Further, in the power storage element according to one aspect of the present invention, the electrode body has a core material forming the winding center portion of the electrode body, and the first protruding portion is inserted into the core material. It may be.

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

Further, in the power storage element according to one aspect of the present invention, the auxiliary member is further provided on the second support portion arranged on the other end surface in the winding axis direction of the electrode body and the second support portion. It may have a second protruding portion inserted into the winding center portion of the electrode body, and the first support portion and the second support portion may be connected to the regulation portion.

According to this configuration, protrusions are inserted into the winding center of the electrode body from both directions parallel to the winding axis direction. Therefore, the frictional force between the inner surface of the container and the electrode body can be further increased, or the movement of the well-balanced electrode body due to the frictional force can be suppressed. Further, since the first support portion and the second support portion are connected to one regulation portion, the two protrusions (first protrusion and second protrusion) have a simple configuration in the longitudinal direction in the cross section of the electrode body. It is possible to suppress the displacement to. That is, damage to the electrode body caused by the two protrusions being displaced in the longitudinal direction can be suppressed by a simple configuration.

Further, in the power storage element according to one aspect of the present invention, the electrode body has a flat portion, and the auxiliary member further has a third support portion connected to the regulation portion, and the third support portion has a third support portion. May be provided with a convex portion for pressing the flat portion of the electrode body.

According to this configuration, the flat portion of the electrode body pushed from the inside to the outside by the first protrusion can be pushed from the outside to the inside by the convex portion of the third support portion. That is, the frictional force between the inner surface of the container and the electrode body can be further increased, and as a result, the suppression of the movement of the electrode body in the container is further ensured.

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, pressure molding or vacuum forming on a single resin sheet, so that mass production is easy. Further, an auxiliary member can 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, a power storage element including an electrode body formed by winding an electrode body and a container for accommodating the electrode body, wherein the movement of the electrode body inside the container is suppressed. Can be provided. That is, according to the present invention, it is possible to provide a power storage element with improved reliability.

It is a perspective view which shows the appearance of the power storage element which concerns on embodiment. It is a perspective view which shows the component arranged in the container of the power storage element which concerns on embodiment. It is a perspective view which shows the structural outline of the electrode body which concerns on embodiment. It is a figure which shows the structural outline when the electrode body which concerns on embodiment is seen from the direction of a winding axis. It is a perspective view which shows the structure of the auxiliary member which concerns on embodiment. It is a 1st partial cross-sectional view of the power storage element which concerns on embodiment. It is a second partial cross-sectional view of the power storage element which concerns on embodiment. It is a perspective view which shows the structural relationship between the auxiliary member and the buried member which concerns on embodiment.

Hereinafter, the power storage element according to the embodiment of the present invention will be described with reference to the drawings. It should be noted that each figure is a schematic view and is not necessarily exactly shown.

Moreover, the embodiment described below shows a specific example of the present invention. The shapes, materials, components, arrangement positions and connection forms of the components, the order of manufacturing processes, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. Further, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept are described as arbitrary components.

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

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

The power storage element 10 is a secondary battery capable of charging electricity and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. For example, the power storage element 10 is a moving body such as an electric vehicle (EV), a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), a motorcycle, a watercraft, a snowmobile, an agricultural machine, a construction machine, or the like. It is used as a battery for driving or starting an engine. The power storage element 10 is not limited to the non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery, or may be a capacitor. Further, the power storage element 10 may be a primary battery that can use the stored electricity without the user having to charge the battery.

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

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

The container 100 is composed of a main body 111 having a rectangular tubular shape and a bottom, and a lid 110 which is a plate-shaped member that closes the opening of the main body 111. Further, the container 100 has a structure in which the inside of the container 100 is sealed by accommodating the electrode body 400 or the like inside and then welding or the like to the lid body 110 and the main body 111. 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 includes a positive electrode plate, a negative electrode plate, and a separator, and is a member capable of storing electricity. The detailed configuration of the electrode body 400 will be described later with reference to 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 110 arranged above the electrode body 400 via an insulating gasket (not shown).

The current collector 120 is a member that is electrically connected to the negative electrode terminal 200 and the negative electrode of the 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, the current collectors 120 and 130 are fixed to the lid 110. Further, the current collector 120 is joined to the negative electrode side end portion of the electrode body 400, and the current collector 130 is joined to the positive electrode side end portion of the electrode body 400. The electrode body 400 is held inside the container 100 in a state of being suspended from the lid body 110 by the current collectors 120 and 130. In this embodiment, each of the current collectors 120 and 130 is bonded to the electrode body 400 by, for example, ultrasonic bonding. 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 in a state where the current collectors 120 and 130 are joined. The auxiliary member 50 is provided in the first support portion 61 arranged on one side in the direction of the winding axis of the electrode body 400 and the first support portion 61, and is inserted into the winding center portion 401 of the electrode body 400. It has a first protruding portion 51 which has been formed. The auxiliary member 50 pushes the electrode body 400 outward from the winding center portion 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 with reference to 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 with reference to FIGS. 3 and 4. FIG. 3 is a perspective view showing an outline of the configuration of the electrode body 400 according to the embodiment. It should be noted that FIG. 3 shows a partially developed element such as a laminated and wound electrode plate. Further, the alternate long and short dash line with the reference numeral W in FIG. 3 represents the winding axis of the electrode body 400. The winding axis W is a virtual axis that serves as a central axis when winding the electrode plate or the like, and in the present embodiment, it is a straight line parallel to the X axis passing through the center of the electrode body 400. That is, in the present 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 when the electrode body 400 according to the embodiment is viewed from the direction of the winding axis W.

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

In the present embodiment, the positive electrode plate 410 has a mixed material layer forming portion 414 in which a positive electrode mixed material layer containing a positive electrode active material is formed on the surface of a long strip-shaped metal foil (positive electrode base material layer 411) made of aluminum. including. The negative electrode plate 420 includes a mixed material layer forming portion 424 in which a negative electrode mixed 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, known materials can be appropriately used as long as they do not impair the performance of the power storage element 10.

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

In the electrode body 400 configured as described above, more specifically, the positive electrode plate 410 and the negative electrode plate 420 are wound around the separator 430 or 450 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 mixed material layer non-forming portion, which is a portion of the base material layer on which the mixed material layer is not formed, at the end portions in the shifted directions.

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

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

As shown in FIG. 4, the electrode body 400 has an elliptical 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 in an oval shape.

Here, the winding center portion 401 has a shaft when the element constituting the electrode body 400 (hereinafter, also referred to as “electrode body element”) such as the negative electrode plate 420 is wound by the winding device. It is the part that forms the cavity that was inserted. That is, the winding center portion 401 is a portion that forms a space existing in the central portion of the electrode body 400 shown in FIG. 4, and in the present embodiment, is a portion that forms the innermost circumference of the electrode body 400. More specifically, in the present embodiment, the electrode body 400 has a core material 480, and the winding center portion 401 is formed by the core material 480.

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

The core material 480 may be a member formed by winding a resin sheet, or may be a member formed into a flat shape. Further, the core material 480 may be an integrally formed member or may be formed of a plurality of members. Further, the material of the core material 480 is not particularly limited. For example, when the separator is placed at the position closest to the core material 480, or when the potential of either the positive electrode or the negative electrode is dropped to the core material 480, a conductive material is used as the material of the core material 480. May be good. 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 the 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 the present embodiment, the auxiliary member 50 is attached to the electrode body 400 after the current collectors 120 and 130 are bonded to the electrode body 400 configured as described above 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 the present embodiment will be described with reference to 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 shown by expanding the elements such as the first support portion 61 connected to the regulation portion 70 so that the configuration of the auxiliary member 50 can be easily visually 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 of the auxiliary member 50 and the electrode body 400.

FIG. 6 is a first partial cross-sectional view of the power storage element 10 according to the embodiment, and FIG. 7 is a second partial cross-sectional view of the 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 simply illustrated. In FIG. 7, a part of the cross section of the power storage element 10 in the XY plane passing through the VII-VII line shown in FIG. 2 is simply illustrated. Further, in FIGS. 6 and 7, the current collector 120 and the like are omitted in order to show the structural relationship between the first protruding portion 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 an electrode body (410, 420) and a container 100 for accommodating the electrode body 400. , Auxiliary member 50 arranged between the inner surface of the container 100 and the electrode body 400 is provided.

The auxiliary member 50 is provided on the first support portion 61 arranged on one side in the direction of the winding axis W of the electrode body 400 and the first support portion 61, and is provided on the winding center portion 401 of the electrode body 400. The inserted first protruding portion 51 and the first support portion 61 are in the longitudinal direction of the cross section (hereinafter referred to as “vertical cross section”) orthogonal to the direction of the winding axis W of the electrode body 400 (in the present embodiment). It is provided with a regulation unit 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 is, for example, as shown in FIG. It is pushed by the first protruding portion 51 in the direction outward from the winding center portion 401. As a result, the frictional force between the inner surface 111a of the main body 111 of the container 100 and the electrode body 400 increases, and as a result, the movement of the electrode body 400 inside the container 100 is suppressed. Specifically, for example, in the flat winding type electrode body 400, the flat portion 405 (see FIG. 4) that tends to be dented inward is extruded outward by the first protruding portion 51, whereby the electrode body 400 and the container are formed. The frictional force between the inner surface 111a of 100 is increased.

Further, the first support portion 61 having the first protrusion 51 is restricted from moving in the longitudinal direction (Z-axis direction) in the vertical cross section of the electrode body 400 by the regulation portion 70. Therefore, for example, damage to the electrode body 400 due to the position of the first protruding portion 51 being displaced in the longitudinal direction (Z-axis direction) with respect to the winding center portion 401 is suppressed. That is, the auxiliary member 50 has the regulating portion 70, so that the winding center portion 401 (see FIG. 4), which has the same flat shape as the outer shape of the electrode body 400, first protrudes in the longitudinal direction (Z-axis direction). The movement of the section 51 is restricted.

Therefore, for example, as shown in FIG. 6, the first protruding portion 51 and the electrode body 400 are formed even when the width of the first protruding portion 51 is shortened with respect to the winding center portion 401 in the Z-axis direction. The possibility of rubbing against each other in the Z-axis direction is reduced.

Here, even if the auxiliary member 50 does not have the regulating portion 70, the width of the first protruding portion 51 in the Z-axis direction is made substantially the same as the width of the winding center portion 401 in the Z-axis direction. Therefore, it is possible to suppress the movement of the first protruding portion 51 in the Z-axis direction without depending on the regulating portion 70. That is, it is possible to suppress the movement of the first protruding portion 51 in the Z-axis direction by bringing both ends of the first protruding portion 51 in the Z-axis direction into contact with the inner surface of the winding center portion 401 in the Z-axis direction. Is. However, in this case, when the first protruding portion 51 tries to move in the Z-axis direction with respect to the electrode body 400, the first protruding portion 51 always makes the inner surface of the winding center portion 401 outward in the Z-axis direction. It will be in a state of being pressed. Further, as in the present embodiment, when the first protruding portion 51 has a long shape in the Z-axis direction and a flat (thin) shape in the Y-axis direction as in the winding center portion 401, The contact area between the first protrusion 51 and the inner surface of the winding center 401 in the Z-axis direction is relatively small. Therefore, when the first protruding portion 51 tries to move in the Z-axis direction, the pressure (pressing pressure per unit area) applied by the first protruding portion 51 to the inner surface of the winding center portion 401 becomes relatively large. As a result, for example, the end portion of the winding center portion 401 in the direction of the winding shaft W may be expanded in the Z-axis direction, and the element such as the negative electrode plate 420 outside the end portion may be damaged. ..

In this regard, the auxiliary member 50 according to the present embodiment has a regulating portion 70 that regulates the movement of the first protruding portion 51 with respect to the electrode body 400 in the Z-axis direction. Therefore, even if the width of the first protruding portion 51 in the Z-axis direction is substantially the same as the width of the winding center portion 401 in the Z-axis direction, the first protruding portion 51 covers the end portion of the winding center portion 401. It is unlikely that a situation will occur in which the product is pushed out in the Z-axis direction.

Further, in the present embodiment, the relationship between the first protruding portion 51 and the winding center portion 401 has a more advantageous structure. Specifically, as shown in FIG. 6, the first protruding portion 51 according to the present embodiment is arranged away from the inner surface of the winding center portion 401 in the Z-axis direction. That is, it is unlikely that the first protruding portion 51 acts 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 having the regulating portion 70 restricts the movement of the first supporting portion 61 having the first protruding portion 51 in the Z-axis direction.

As described above, according to the auxiliary member 50 according to the present embodiment, the positional deviation of the first protrusion 51 in the Z-axis direction is suppressed without depending on the inner surface of the winding center portion 401 in the Z-axis direction. can do. That is, the first protruding portion 51 is arranged in a state where unnecessary stress is not applied 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 the present embodiment, for example, as shown in FIG. 6, when viewed from a direction orthogonal to the winding axis W, the first protruding portion 51 arranged on the negative electrode side is the mixture layer forming portion 424. It has an overlapping length (a length that reaches the mixture layer forming portion 424). In other words, the first protruding portion 51 has a length exceeding the mixture layer non-forming portion 421a, which is a portion where the negative electrode base material layer 421 is exposed. That is, the first protruding portion 51 is inserted to a relatively deep position of the winding center portion 401, whereby the electrode body 400 is pushed outward from the winding center portion 401 to form an electrode. The effectiveness of suppressing the movement of the body 400 is improved.

Further, in the present embodiment, the regulating portion 70 is connected to the first support portion 61 and is arranged on the side surface in the longitudinal direction (Z-axis direction) of the vertical cross section of the electrode body 400. That is, for example, when the regulating portion 70 is in contact with or is in contact with the side surface of the electrode body 400, the movement of the first protruding portion 51 in the longitudinal direction is restricted. In this way, with a simple configuration in which the regulating portion 70 is arranged on the side surface of the electrode body 400 in the longitudinal direction of the vertical cross section, the positional deviation of the first protruding portion 51 in the longitudinal direction can be suppressed.

In the present embodiment, the regulation unit 70 and the first support unit 61 are directly connected, but between the regulation unit 70 and the first support unit 61, for example, the regulation unit 70 and the first support unit 61. A connecting portion, which is a separate member from the support portion 61, may be interposed. That is, the regulation unit 70 and the first support unit 61 may be indirectly connected. Even in this case, by restricting the movement of the regulating portion 70, the movement of the first supporting portion 61 and the first protruding portion 51 of the first supporting portion 61 is restricted.

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 the present embodiment), and the regulating unit 70 is shown in FIG. 6, for example. As shown, it is arranged between the electrode body 400 and the surface of the container 100 facing the one surface (in this embodiment, the bottom surface 111b of the container 100).

According to this configuration, the regulating portion 70 is arranged between the side surface of the electrode body 400 and the inner surface (bottom surface 111b) of the container 100, and the vertical section of the electrode body 400 of the first protruding portion 51 is performed. Bidirectional misalignment parallel to the longitudinal direction of the surface is suppressed.

Further, in the present embodiment, the width of the first protruding portion 51 in the lateral direction (Y-axis direction in the present embodiment) of the vertical cross section of the electrode body 400 is, for example, as shown in FIGS. 5 and 7. The taper 51a is provided so as to become narrower as the distance from the first support portion 61 increases.

Since the first protruding portion 51 has the taper 51a, for example, the first protruding portion 51 can be smoothly inserted into the winding center portion 401. In this case, the first protruding portion 51 is formed while suppressing deformation (creation of wrinkles) of the inner surface of the winding center portion 401 due to the insertion of the first protruding portion 51 into the winding center portion 401 of the electrode body 400. , It is possible to insert the electrode body 400 to the inside more reliably. Further, since the taper 51a is formed so that the lateral width (width in the Y-axis direction) becomes narrow, the flat portion 405 of the electrode body 400 can be efficiently pushed outward.

In the present embodiment, in the first protrusion 51, the taper 51a is continuously formed from the tip in the X-axis direction to the root (the connection portion with the first support portion 61), but in the X-axis direction. The taper 51a may be formed only in a part from the tip to the root. For example, in the first protrusion 51, both sides in the Y-axis direction may be formed parallel to the X-axis direction from the tip to a predetermined position, and a taper 51a may be formed from the predetermined position to the root. Even in this case, since the tip of the first protruding portion 51 is relatively thin, the ease of insertion into the winding center portion 401 is ensured. Further, since the first protruding portion 51 is formed with a portion gradually thickened by the taper 51a, the flat portion 405 of the electrode body 400 can be efficiently pushed outward.

Further, in the present embodiment, the electrode body 400 has a core material 480 forming the winding center portion 401 of the electrode body 400, and the first protruding portion 51 is inserted into the core material 480.

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

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

In addition, in FIGS. 6 and 7, the configuration of the negative electrode side (plus side in the X-axis direction) of the auxiliary member 50 is illustrated and described, but the auxiliary member 50 according to the present embodiment is, for example, FIG. As shown in the above, a protrusion or the like is also provided on the positive electrode side (minus side in the X-axis direction).

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

According to this configuration, 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, the frictional force between the inner surface 111a of the container 100 and the electrode body 400 can be further increased, or the movement of the well-balanced electrode body 400 due to the frictional force can be suppressed.

Further, since the first support portion 61 and the second support portion 62 are connected to one regulation portion 70, the electrodes of the two protrusions (first protrusion 51 and second protrusion 52) have a simple configuration. Positional deviation in the longitudinal direction (Z-axis direction) in the vertical cross section of the body 400 can be suppressed. That is, damage to the electrode body 400 caused by the two protrusions (first protrusion 51 and second protrusion 52) being displaced in the longitudinal direction can be suppressed by a simple configuration.

Further, in the present embodiment, the second protruding portion 52 has a taper 52a so that the width of the vertical cross section of the electrode body 400 in the lateral direction becomes narrower as the distance from the second support portion 62 increases. As a result, the second protruding portion 52 can be smoothly inserted into the winding center portion 401, and the flat portion 405 of the electrode body 400 can be efficiently pushed outward. ..

Further, in the present embodiment, the electrode body 400 has a flat portion 405 as shown in FIG. 4, for example, and the auxiliary member 50 is further connected to the regulating portion 70 as shown in FIG. 5, for example. It has three support portions 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 portion 405 of the electrode body 400 pushed from the inside to the outside by the first protrusion 51 is pushed from the outside to the inside by the convex portion 81 of the third support portion 63. Can be done (see FIGS. 5 and 7). That is, 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 suppression of the movement of the electrode body 400 in the container 100 is further ensured.

In the present embodiment, the auxiliary member 50 has a pair of third support portions 63 arranged so as to face each other in the lateral direction (Y-axis direction) of the vertical cross section of the electrode body 400. Therefore, for example, the flat portion 405 of the electrode body 400 can be supported by a pair of convex portions 81 from both sides in the Y-axis direction. This is advantageous from the viewpoint of suppressing the movement of the electrode body 400.

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

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

As described above, the auxiliary member 50 can be manufactured by, for example, pressing molding on one sheet made of resin, so that mass production is easy. Further, the auxiliary member 50 can be realized by the 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. That is, the auxiliary member 50 according to the present embodiment is suitable as a member for suppressing the movement of the electrode body 400 in the power storage element 10 having the container 100 which is not dropped to the positive electrode potential or the negative electrode potential of the electrode body 400.

When the auxiliary member 50 is formed of a single sheet-like material, a cavity is formed inside the first protruding portion 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 suppressing the movement of the electrode body 400 by the first protrusion 51.

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 forming 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, the shape and size of both side surfaces in the Y-axis direction along the inner surfaces of both sides in the Y-axis direction of the recess 71. It is molded into.

By arranging the embedded member 90 inside the recess 71 of the first protrusion 51 in this way, even when 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.

That is, by forming the auxiliary member 50 with 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 suppressing effect can be improved.

Although the configuration in which the buried member 90 is arranged in the recess 71 of the first protrusion 51 is shown in FIG. 8, the buried member 90 may be arranged in the recess of the second protrusion 52. As a result, the effect of improving the hardness of the second protruding portion 52 can be obtained.

Further, in the present embodiment, the convex portion 81 provided on the third support portion 63 of the auxiliary member 50 is a portion formed by pressure forming or the like, like the first protruding portion 51, and is opposite to the protruding direction. A recess is formed on the side (see, for example, FIG. 7). Therefore, an embedded member may be arranged in this recess. As a result, the convex portion 81 can be made hard, and as a result, the effect of suppressing the movement of the electrode body 400 by pressing the convex portion 81 against the electrode body 400 is improved.

(Other embodiments)
The power storage element and the manufacturing method thereof according to the present invention have been described above based on the embodiments. However, the present invention is not limited to the above embodiment. As long as it does not deviate from the gist of the present invention, a form in which various modifications conceived by those skilled in the art are applied to the above-described embodiment, or a form constructed by combining a plurality of the above-described components is also within the scope of the present invention. include.

For example, the auxiliary member 50 may not be formed of a single sheet-like material. For example, a three-dimensional member such as the first protruding portion 51, which is separate from the base member, is adhered to one sheet-shaped base member forming a flat plate-shaped portion such as the regulation portion 70 and the first support portion 61. Alternatively, the auxiliary member 50 may be formed by welding. In this case, for example, the first protruding portion 51 can be manufactured as a solid member, whereby the first protruding portion 51 can be manufactured as a relatively hard member.

Further, for example, the shape of the container 100 included in the power storage element 10 does not have to be the rectangular parallelepiped shape as shown in FIG. For example, the auxiliary member 50 is arranged in the power storage element 10 including the container 100 that accommodates the winding type electrode body 400 and has an elliptical or oval shape when viewed from the direction of the winding axis W. May be done.

That is, even if the shape of the container 100 is not a rectangular parallelepiped shape, the regulating portion 70 is arranged on the side surface of the electrode body 400 in the direction orthogonal to the winding axis W, so that the regulating portion 70 is at least an electrode body. Movement is restricted by contact with 400. As a result, the movement of the first protruding portion 51 included in the first support portion 61 connected to the regulating portion 70 is restricted. Therefore, as described in the above embodiment, there is an effect that the movement of the electrode body 400 in the container 100 can be suppressed in a manner in which unnecessary stress is not applied to the electrode body 400.

Further, in the present embodiment, the power storage element 10 includes only one electrode body 400, but the number of electrode bodies 400 included in the power storage element 10 may be two or more. For example, when the power storage element 10 includes two electrode bodies 400, the current collector 120 may have four legs joined to the 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 in the first support portion 61. Even in this case, it is possible to obtain the effect of suppressing the movement of the two electrode bodies 400 in the container 100.

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

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

10 Power storage element 50 Auxiliary member 51 First protrusion 51a, 52a Tapered 52 Second protrusion 61 First support 62 Second support 63 Third support 70 Restriction 71 Recess 81 Convex 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 405 Flat part 410 Positive electrode plate 420 Negative electrode plate 480 Core material

Claims (4)

The electrode body formed by winding the electrode plate and
A container for accommodating the electrode body and
An auxiliary member arranged between the inner surface of the container and the electrode body is provided.
The electrode body has a flat portion and has a flat portion.
The auxiliary member is
A flat plate-shaped support portion arranged on the side in the lateral direction of the cross section orthogonal to the winding axis direction of the electrode body, and
It is a convex portion provided on the support portion and presses the flat portion of the electrode body, and when viewed from the protruding direction of the convex portion, the flat portion of the support portion is formed on the entire circumference of the convex portion. Convex parts arranged in a positioned state and
A regulating portion connected to the support portion and arranged laterally in the longitudinal direction of the cross section orthogonal to the winding axis direction of the electrode body is provided.
The convex portion has a concave portion forming a cavity inside the convex portion, and an embedded member different from the convex portion is embedded in the concave portion.
Power storage element. The convex portion is formed in a square shape when viewed from the protruding direction.
The power storage element according to claim 1 . The convex portion is arranged in a state where the flat portion is recessed by pressing the flat portion of the electrode body.
The power storage element according to claim 1 or 2 . The power storage element according to any one of claims 1 to 3 , wherein the auxiliary member is made of one sheet-like material.

Images