JP6874695B2 - Power storage element and manufacturing method of power storage element - Google Patents

Description

The present invention relates to a power storage element including an electrode body and a current collector connected to the electrode body, and a method for manufacturing the power storage element.

A power storage element having an electrode body and a current collector and having a configuration in which the electrode body and the current collector are connected is widely known. Then, conventionally, a power storage element for connecting an electrode body and a current collector by inserting the electrode body between a pair of legs of the current collector and joining the electrode body and the legs has been proposed. (See, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-71109

In the conventional power storage element, when the electrode body is inserted between the pair of legs of the current collector, the end portion of the electrode body may be caught by the legs and the electrode body may be damaged.

An object of the present invention is to provide a power storage element and a method for manufacturing a power storage element capable of suppressing damage to the electrode body when the electrode body and the current collector are connected.

The power storage element according to one aspect of the present invention includes a winding type electrode body and a current collector connected to the electrode body, and the current collector includes a terminal connection portion and a terminal connection portion to the second. The electrode body has a pair of legs extending in one direction and arranged in a second direction orthogonal to the first direction, and the electrode body has a first part arranged between the pair of legs, and the first portion is provided. A part has a tip portion facing the terminal connection portion in the first direction and a second portion having a width narrower in the second direction than the tip portion.

According to the power storage element of the present invention, it is possible to suppress damage to the electrode body when the electrode body and the current collector are connected.

FIG. 1 is a perspective view schematically showing the appearance of the power storage element according to the embodiment of the present invention. FIG. 2 is a perspective view showing components arranged in the container of the power storage element. FIG. 3 is an exploded perspective view of the power storage element. FIG. 4 is a perspective view showing the configuration of the positive electrode current collector. FIG. 5 is a plan view showing the configuration of the positive electrode current collector. FIG. 6 is a perspective view showing the configuration of the electrode body. FIG. 7 is a plan view showing the configuration of the electrode body. FIG. 8 is a plan view showing a state in which the electrode body is connected to the positive electrode current collector.

The power storage element according to one aspect of the present invention includes a winding type electrode body and a current collector connected to the electrode body, and the current collector includes a terminal connection portion and a terminal connection portion to the second. The electrode body has a pair of legs extending in one direction and arranged in a second direction orthogonal to the first direction, and the electrode body has a first part arranged between the pair of legs, and the first portion is provided. A part has a tip portion facing the terminal connection portion in the first direction and a second portion having a width narrower in the second direction than the tip portion.

In the power storage element, the electrode body is formed with a tip portion and a portion narrower than the tip portion (second part) at a portion (first part) arranged between a pair of legs of the current collector. ing. Since the second portion having a narrow width is formed in the first portion of the electrode body, the width of the entire first portion can be narrowed. As a result, when the first part is inserted between the pair of legs of the current collector, the end of the first part is prevented from being caught by the legs, and the first part is placed between the pair of legs. It can be easily inserted. Therefore, it is possible to prevent the electrode body from being damaged when the electrode body and the current collector are connected.

The second part may have a curved surface on the side surface in the second direction.

According to this, it is possible to suppress the occurrence of sharp wrinkles (sharp edges) in the electrode body. If a sharp edge occurs, it may break through the separator and cause a short circuit between the positive electrode and the negative electrode of the electrode body. By suppressing the occurrence of sharp edges, the occurrence of the short circuit can be suppressed.

The second part may have a shape in which both side surfaces in the second direction are recessed.

According to this, the end portion of the first portion may be recessed from both sides to form the second portion, and the second portion can be easily formed.

The distance between the pair of legs may be narrower than the maximum width of the electrode body in the second direction.

According to this, even when the distance between the pair of legs of the current collector is narrower than the maximum width of the electrode body, the electrode body has the second part. The first part can be easily inserted between the pair of legs.

The current collector further has a connecting portion for connecting the pair of legs, and the pair of legs is arranged so that the space between the pair of legs is narrower on the connecting portion side. The second portion may be formed at the end portion of the first portion on the connecting portion side.

According to this, even in a current collector having a narrow gap on the connecting portion side, the first part of the electrode body can be easily inserted between the pair of legs. Therefore, in the power storage element, it is possible to prevent the electrode body from being damaged when the electrode body and the current collector are connected to each other.

The first part may have a third part having a width wider in the second direction than the second part at a position sandwiching the second part with the tip part.

According to this, since it is sufficient to form the second portion by denting between the tip portion of the first portion and the third portion of the electrode body, the second portion can be easily formed.

The third portion may be a joint portion to be joined to the pair of leg portions.

According to this, since it is sufficient to form the second portion by denting between the tip portion of the first portion and the joint portion of the electrode body, the second portion can be easily formed.

The second portion may be arranged at a position overlapping the curved portion of the innermost circumference of the electrode body when viewed from the second direction.

In the electrode body, when the second part is arranged on the tip side of the curved part of the innermost circumference when viewed from the second direction, the electrode plate is crushed when forming the second part, and a sharp edge is formed. It may occur. Further, when the second part is arranged on the central part side of the curved part of the innermost circumference, the second part is formed at a place overlapping with the winding space, so that the second part is formed due to the repulsion of the electrode plate or the like. Becomes difficult. Therefore, in the electrode body, the second portion is arranged at a position where it overlaps with the curved portion of the innermost circumference when viewed from the second direction, thereby suppressing the sharp edge generated when the second portion is formed. The second part can be easily formed.

The method for manufacturing a power storage element according to one aspect of the present invention is a power storage element including an electrode body and a current collector connected to the electrode body and having a pair of legs extending in the first direction and lining up in the second direction. The first part having an end portion of the electrode body is pressed in the second direction to the end portion in the first direction than the tip end portion of the first part. A second part forming step of forming a second part having a narrow width in two directions, a first part arranging step of arranging the first part between the pair of legs, and the first part and the pair of legs. Includes a joining step of joining the parts.

According to this, in the method of manufacturing a power storage element, the first part having an end portion of the electrode body is pressed to form a second portion narrower than the tip portion at the end portion, and the first part is formed. It is arranged between the pair of legs of the current collector, and the first part and the pair of legs are joined. That is, by forming the second portion having a narrow width in the first part of the electrode body, the width of the entire end portion can be narrowed. As a result, the first part is suppressed from being caught by the pair of legs of the current collector, the first part is easily inserted between the pair of legs, and the electrode body and the current collector are joined. be able to. Therefore, it is possible to prevent the electrode body from being damaged.

The present invention can be realized not only as such a power storage element and a method for manufacturing the same, but also as an electrode body included in the power storage element and a method for manufacturing the same.

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 all of the embodiments described below show a preferred specific example of the present invention. Numerical values, shapes, materials, components, arrangement positions of components, connection forms, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. 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. Further, each figure is a schematic view, and the dimensions and the like are not necessarily exactly shown.

(Embodiment)
First, the configuration of the power storage element 10 will be described.

FIG. 1 is a perspective view schematically showing the appearance of the power storage element 10 according to the embodiment of the present invention. FIG. 2 is a perspective view showing components arranged in the container 100 of the power storage element 10. FIG. 2 is a perspective view showing a state in which the container body 111 is separated from the power storage element 10. FIG. 2 shows a state after the positive electrode current collector 500 and the negative electrode current collector 600 are joined to the electrode bodies 410 and 420.

FIG. 3 is an exploded perspective view of the power storage element 10. FIG. 3 shows a state before joining the positive electrode current collector 500 and the negative electrode current collector 600 to the electrode bodies 410 and 420. In FIG. 3, the container body 111 is not shown.

The X-axis direction, the Y-axis direction, and the Z-axis direction shown in these figures are directions orthogonal to each other. In these figures, the Z-axis direction is shown as the vertical direction, and the Z-axis direction will be described below as the vertical direction. Since the Z-axis direction may not be the vertical direction depending on the usage mode, the Z-axis direction is not limited to the vertical direction. The same applies to the following figures.

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 applied to a power source for automobiles such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), a power source for electronic devices, a power source for power storage, and the like. ..

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, a capacitor, or a primary battery. .. In the present embodiment, the rectangular (square) power storage element 10 is illustrated, but the shape of the power storage element 10 is not limited to the rectangular shape, and may be a cylindrical shape, a long cylindrical shape, or the like. However, it can also be a laminated type power storage element.

As shown in FIG. 1, the power storage element 10 includes a container 100, a positive electrode terminal 200, and a negative electrode terminal 300. As shown in FIG. 2, the electrode bodies 410 and 420, the positive electrode current collector 500, and the negative electrode current collector 600 are housed in the container 100.

In addition to the above components, spacers arranged on the sides of the positive electrode current collector 500 and the negative electrode current collector 600, a gas discharge valve for releasing the pressure in the container 100 when the pressure rises, and an electrode body. An insulating film or the like that wraps 410, 420, etc. may be arranged. A liquid such as an electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100, but the illustration of the liquid is omitted. The type of electrolytic solution 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 container 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 container main body 111. The inside of the container 100 is sealed by accommodating the electrode bodies 410, 420 and the like inside, and then welding the lid body 110 and the container body 111. The materials of the lid 110 and the container body 111 are not particularly limited, and may be weldable metals such as stainless steel, aluminum, and aluminum alloy. Alternatively, a resin can be used.

The electrode bodies 410 and 420 are two storage elements (power generation elements) that include a positive electrode plate, a negative electrode plate, and a separator and can store electricity. The electrode bodies 410 and 420 are arranged side by side in the Y-axis direction.

The positive electrode plates of the electrodes 410 and 420 are formed by forming a positive electrode active material layer on a positive electrode base material layer which is a long strip-shaped current collecting foil made of aluminum, an aluminum alloy, or the like. The negative electrode plate is formed by forming a negative electrode active material layer on a negative electrode base material layer which is a long strip-shaped current collecting foil made of copper, a copper alloy, or the like. As the separator, for example, a microporous sheet made of resin or a non-woven fabric can be used. As the current collecting foil, known materials such as nickel, iron, stainless steel, titanium, calcined carbon, conductive polymer, conductive glass, and Al—Cd alloy can also be used as appropriate.

The electrode bodies 410 and 420 are formed by winding those arranged in layers so that the separator is sandwiched between the positive electrode plate and the negative electrode plate. Specifically, in the electrode bodies 410 and 420, the positive electrode plate and the negative electrode plate are wound by being displaced from each other in the direction of the winding axis (virtual axis parallel to the X-axis direction in the present embodiment) via the separator. It is being turned. Then, in the positive electrode plate and the negative electrode plate, a portion where the active material is not coated (the active material layer is not formed) and the base material layer is exposed (active material uncoated portion) is applied to the edge portions in the shifted directions. Part).

The electrode body 410 has a positive electrode focusing portion 411 in which the active material uncoated portion of the positive electrode plate is laminated and bundled at one end portion in the winding axis direction (the end portion on the plus side in the X axis direction). The electrode body 420 has a positive electrode focusing portion 421 at one end in the winding axis direction (end on the plus side in the X-axis direction). The electrode body 410 has a negative electrode focusing portion 412 in which the active material uncoated portion of the negative electrode plate is laminated and bundled at the other end portion in the winding axis direction (the end portion on the minus side in the X axis direction). In addition, the electrode body 420 has a negative electrode focusing portion 422 at the other end in the winding axis direction (the end on the minus side in the X-axis direction). For example, the thickness of the active material uncoated portion (current collector foil) of the positive electrode plate and the negative electrode plate is about 5 μm to 20 μm, and each of the positive electrode focusing portions 411 and 421 and the negative electrode focusing portions 412 and 422 is the active material. The uncoated portion is formed by bundling, for example, about 30 to 40 sheets. A detailed configuration of the positive electrode focusing portions 411 and 421 and the negative electrode focusing portions 412 and 422 included in the electrode bodies 410 and 420 will be described later.

As the positive electrode active material used for the positive electrode active material layer, any known material can be appropriately used as long as it is a positive electrode active material that can occlude and release lithium ions. For example, _{a composite oxide represented by Li x} MO _y (M represents at least one transition metal) (Li _x CoO ₂ , Li _x NiO ₂ , Li _x Mn ₂ O ₄ , Li _x MnO ₃ , Li _x Ni). _y Co _(1-y) O ₂ , Li _x N _y Mn _z Co _(1-y-z) O ₂ , Li _x N _y Mn _(2-y) O ₄ etc.), or Li _w Me _x (XO) _y ) _z (Me represents at least one transition metal, X represents, for example, P, Si, B, V) polyanionic compounds (LiFePO ₄ , LiMnPO ₄ , LiNiPO ₄ , LiCoPO ₄ , Li ₃ V ₂ (PO) ₄ ) ₃ , Li ₂ MnSiO ₄ , Li ₂ CoPO ₄ F, etc.) can be selected. The elements or polyanions in these compounds may be partially substituted with other elements or anion species. Further, examples thereof include, but are not limited to, conductive polymer compounds such as disulfide, polypyrrole, polyaniline, polyparastyrene, polyacetylene, and polyacene-based materials, and pseudo-graphite structural carbonaceous materials. These may be used alone or in any combination and ratio of two or more.

As the negative electrode active material used for the negative electrode active material layer, a known material can be appropriately used as long as it is a negative electrode active material capable of occluding and releasing lithium ions. For example, in addition to lithium metals and lithium alloys (lithium metal-containing alloys such as lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and wood alloys), lithium can be stored and released. Alloys, carbon materials (eg graphite, non-graphitizable carbon, easily graphitized carbon, low temperature fired carbon, amorphous carbon, etc.), metal oxides, lithium metal oxides (Li ₄ Ti ₅ O _12, etc.), polyphosphate compounds And so on. These may be used alone or in any combination and ratio of two or more.

In the present embodiment, the cross-sectional shape of the electrode bodies 410 and 420 is shown as an oval shape, but an elliptical shape or the like may be used. Further, the electrode body is not limited to the wound type, and may have a shape in which flat plate-shaped electrode plates are laminated or a shape in which the electrode plates are folded in a bellows shape.

The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode plates of the electrode bodies 410 and 420, and the negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode plate of the electrode bodies 410 and 420. The positive electrode terminal 200 and the negative electrode terminal 300 are made of metal, and the electricity stored in the electrode bodies 410 and 420 is led out to the external space of the power storage element 10, and the power storage element is used to store electricity in the electrode bodies 410 and 420. Electricity is introduced into the internal space of 10.

The positive electrode terminal 200 and the negative electrode terminal 300 are attached to the lid 110 arranged above the electrode bodies 410 and 420. Specifically, as shown in FIG. 3, in the positive electrode terminal 200, the shaft portion 210 is inserted into the through hole 110a of the lid 110 and the opening 511 of the positive electrode current collector 500 and crimped to obtain a positive electrode. It is fixed to the lid 110 together with the current collector 500. Similarly, in the negative electrode terminal 300, the shaft portion 310 is inserted into the through hole 110b of the lid 110 and the opening 611 of the negative electrode current collector 600 and crimped so that the negative electrode terminal 300 and the negative electrode current collector 600 are inserted into the lid 110. It is fixed.

The material of the positive electrode terminal 200 is not limited, but is made of aluminum or an aluminum alloy, for example, like the positive electrode base material layers of the electrode bodies 410 and 420. The material of the negative electrode terminal 300 is not limited, but for example, the shaft portion 310 is formed of copper or a copper alloy, like the negative electrode base material layers of the electrode bodies 410 and 420, and the portion other than the shaft portion 310 is aluminum. Alternatively, it is made of an aluminum alloy or the like.

Gaskets are arranged between the lid 110 and the positive electrode terminal 200 and between the lid 110 and the positive electrode current collector 500 in order to ensure insulation and airtightness, but the illustration is omitted. There is. The same applies to the negative electrode side.

The positive electrode current collector 500 is arranged in the vicinity of the positive electrode focusing portions 411 and 421 of the electrode bodies 410 and 420, and has conductivity and rigidity that are electrically connected to the positive electrode terminals 200 and the positive electrode plates of the electrode bodies 410 and 420. It is a member provided with. The negative electrode current collector 600 is arranged in the vicinity of the negative electrode focusing portions 412 and 422 of the electrode bodies 410 and 420, and has conductivity and rigidity that are electrically connected to the negative electrode terminals 300 and the negative electrode plates of the electrode bodies 410 and 420. It is a member provided with.

The positive electrode current collector 500 and the negative electrode current collector 600 are conductive plate-shaped members arranged in a bent state along the side wall and the lid 110 from the side wall of the container body 111 to the lid 110. The positive electrode current collector 500 and the negative electrode current collector 600 are fixedly connected (joined) to the lid 110. The positive electrode current collector 500 and the negative electrode current collector 600 are fixedly connected (bonded) to the positive electrode focusing portions 411 and 421 and the negative electrode focusing portions 412 and 422 of the electrode bodies 410 and 420, respectively. With this configuration, the electrode bodies 410 and 420 are held (supported) in a state of being suspended from the lid 110 by the positive electrode current collector 500 and the negative electrode current collector 600, and shaking due to vibration, impact, or the like is suppressed.

The material of the positive electrode current collector 500 is not limited, but is formed of, for example, aluminum or an aluminum alloy like the positive electrode base material layers of the electrode bodies 410 and 420. The material of the negative electrode current collector 600 is not limited, but is made of copper or a copper alloy, for example, like the negative electrode base material layers of the electrode bodies 410 and 420.

Since the positive electrode current collector 500 and the negative electrode current collector 600 have the same configuration, the configuration of the positive electrode current collector 500 will be described below, and the description of the configuration of the negative electrode current collector 600 will be omitted. ..

FIG. 4 is a perspective view showing the configuration of the positive electrode current collector 500 according to the embodiment of the present invention. Further, FIG. 5 is a plan view showing the configuration of the positive electrode current collector 500. FIG. 5 shows a configuration when the positive electrode current collector 500 shown in FIG. 4 is viewed from the positive side in the X-axis direction.

As shown in these figures, the positive electrode current collector 500 extends from the positive side in the X-axis direction to the negative side in the Z-axis direction of the terminal connection portion 510 and the terminal connection portion 510, and is an electrode connection arranged in the Y-axis direction. It has parts 520 to 550.

The terminal connection portion 510 is a portion connected to the positive electrode terminal 200. That is, the terminal connection portion 510 is a flat plate-shaped portion arranged on the positive electrode terminal 200 side (upper side, positive side in the Z-axis direction) of the positive electrode current collector 500, and is electrically and mechanically (physically) connected to the positive electrode terminal 200. ) Is connected.

The terminal connection portion 510 is formed with an opening 511 which is a circular through hole into which the shaft portion 210 of the positive electrode terminal 200 is inserted. The terminal connection portion 510 is fixed to the positive electrode terminal 200 by inserting the shaft portion 210 into the opening 511 and crimping it together with the lid 110. The shaft portion 210 is, for example, a rivet, and the terminal connecting portion 510 is fixed to the lid 110 together with the positive electrode terminal 200 by caulking with the rivet.

The opening 511 is not limited to a circular shape, and may be an elliptical shape, a rectangular shape, or another polygonal shape, but a shape corresponding to the outer shape of the shaft portion 210 is preferable. The opening 511 is not limited to the through hole, and may be a notch cut out in a semicircular shape or a rectangular shape.

The terminal connection portion 510 is arranged above the electrode connection portions 520 to 550 and connects the electrode connection portions 520 to 550. The terminal connection portion 510 connects a pair of electrode connection portions 520 and 530, connects a pair of electrode connection portions 540 and 550, and further connects an electrode connection portion 520 and 530 and an electrode connection portion 540 and 550. Hereinafter, the electrode connection portions 520 to 550 will be described in detail.

The electrode connecting portions 520 to 550 are portions connected to the electrode bodies 410 and 420. That is, the electrode connection portions 520 to 550 are flat plate-shaped portions arranged on the electrode bodies 410 and 420 sides (lower side, negative side in the Z-axis direction) of the positive electrode current collector 500, and the electrode bodies 410 and 420 are electrically connected. Connected physically and mechanically. Specifically, the electrode connecting portions 520 to 550 are joined to the positive electrode focusing portions 411 and 421 of the electrode bodies 410 and 420 by welding such as resistance welding or ultrasonic welding or caulking.

The electrode connecting portion 520 has a long and flat plate shape extending from the end of the terminal connecting portion 510 on the negative side in the Y-axis direction on the positive side in the X-axis direction so as to hang down toward the negative side in the Z-axis direction. It is connected to the side surface of the positive electrode focusing portion 411 on the negative side in the Y-axis direction. The electrode connection portion 530 is long and elongated so as to hang down from the central portion of the side surface of the terminal connection portion 510 on the plus side in the X-axis direction (closer to the minus side in the Y-axis direction) toward the minus side in the Z-axis direction. It is a flat plate-shaped portion, and is connected to the side surface of the positive electrode focusing portion 411 on the positive side in the Y-axis direction. The electrode connecting portions 520 and 530 are joined to the positive electrode focusing portion 411 so as to sandwich the positive electrode focusing portion 411 of the electrode body 410 from both sides in the Y-axis direction.

The electrode connection portion 540 is long and elongated so as to hang down from the central portion of the side surface of the terminal connection portion 510 on the plus side in the X-axis direction (closer to the plus side in the Y-axis direction) toward the minus side in the Z-axis direction. It is a flat plate-shaped portion, and is connected to the side surface of the positive electrode focusing portion 421 on the negative side in the Y-axis direction. The electrode connection portion 550 has a long and flat plate shape extending from the end of the terminal connection portion 510 on the positive side in the Y-axis direction on the positive side in the X-axis direction so as to hang down toward the negative side in the Z-axis direction. It is connected to the side surface of the positive electrode focusing portion 421 on the positive side in the Y-axis direction. The electrode connecting portions 540 and 550 are joined to the positive electrode focusing portion 421 so as to sandwich the positive electrode focusing portion 421 of the electrode body 420 from both sides in the Y-axis direction.

The electrode connecting portions 520 and 530 are examples of a pair of leg portions extending in the Z-axis direction (first direction) and lined up in the Y-axis direction (second direction). The electrode connecting portions 540 and 550 are another example of a pair of legs extending in the Z-axis direction (first direction) and aligned in the Y-axis direction (second direction). The terminal connection portion 510 is an example of a connecting portion that connects a pair of legs. Each of the positive electrode focusing portions 411 and 421 is an example of the first part arranged between the pair of legs. The same applies to the negative electrode side.

As shown in FIG. 5, the electrode connecting portions 520 and 530, which are a pair of legs, are arranged so that the space between the pair of legs is narrower on the terminal connecting portion 510 side, which is a connecting portion. ing. That is, the electrode connection portions 520 and 530 are arranged so that the space between them is narrower in the width W1 on the terminal connection portion 510 side than in the width W2 on the side opposite to the terminal connection portion 510. Similarly, the electrode connection portions 540 and 550 are arranged so that the space between them is narrower on the terminal connection portion 510 side than on the side opposite to the terminal connection portion 510.

Next, the specific configurations of the electrode bodies 410 and 420 will be described in detail. In particular, the detailed configurations of the positive electrode focusing portions 411 and 421 and the negative electrode focusing portions 412 and 422 included in the electrode bodies 410 and 420 will be described. Since the electrode body 410 and the electrode body 420 have the same configuration, the configuration of the electrode body 410 will be mainly described below, and the description of the configuration of the electrode body 420 will be simplified or omitted. Further, since the positive electrode focusing portion 411 and the negative electrode focusing portion 412 of the electrode body 410 have the same configuration, the configuration of the positive electrode focusing portion 411 will be mainly described below, and the configuration of the negative electrode focusing portion 412 will be described below. The description is simplified or omitted.

FIG. 6 is a perspective view showing the configuration of the electrode body 410 according to the embodiment of the present invention. Further, FIG. 7 is a plan view showing the configuration of the electrode body 410 according to the embodiment of the present invention. Specifically, the figure shows a configuration when the electrode body 410 shown in FIG. 6 is viewed from the plus side in the X-axis direction. Further, FIG. 8 is a plan view showing a configuration in which the electrode bodies 410 and 420 according to the embodiment of the present invention are connected to the positive electrode current collector 500. In these figures, in particular, the configuration of the positive electrode focusing portion 411 of the electrode body 410 is shown in detail.

As shown in these figures, the positive electrode focusing portion 411 of the electrode body 410 is a first end portion 411a which is an end portion on the positive side in the Z-axis direction, a joint portion 411d, and an end portion on the negative side in the Z-axis direction. It has a second end portion 411e.

The first end portion 411a is an end portion of the positive electrode focusing portion 411 arranged on the terminal connecting portion 510 side of the positive electrode current collector 500. That is, the first end portion 411a is an end portion in the direction intersecting the winding axis direction of the positive electrode focusing portion 411. Further, the first end portion 411a is formed to be narrower in width than the joint portion 411d and the second end portion 411e in the Y-axis direction. Further, the outer edge of the first end portion 411a is formed by a gentle curve in the cross section when cut in the YZ plane. That is, the first end portion 411a is a curved portion whose side surface is formed by a gently curved surface. Here, the first end portion 411a has a tip portion 411b and a narrow portion 411c.

The tip portion 411b is a tip portion of the first end portion 411a (the tip portion of the positive electrode focusing portion 411 on the terminal connection portion 510 side) and faces the terminal connection portion 510. The outer edge of the tip portion 411b is formed in a substantially semicircular arc shape in a cross section when cut in a YZ plane. That is, the tip portion 411b has a shape similar to that of a truncated cone.

Further, the tip portion 411b is arranged in a space between the electrode connecting portions 520 and 530 where the width on the terminal connecting portion 510 side is narrow (a portion corresponding to the width W1 in FIG. 5). That is, the tip portion 411b is arranged at a position corresponding to the narrow portion between the electrode connecting portions 520 and 530, and in the present embodiment, the tip portion 411b is the electrode body 410 in the Y-axis direction. It is arranged at a position slightly deviated from the center position to the minus side in the Y-axis direction.

The narrow portion 411c is arranged below the tip portion 411b (minus side in the Z-axis direction) so as to be connected to the lower end of the tip portion 411b. The narrow portion 411c has a shape in which both side surfaces of the first end portion 411a in the Y-axis direction are recessed, and the side surfaces are formed with a curved surface. That is, the width of the narrow portion 411c in the Y-axis direction is formed to be narrower than the maximum width of the tip portion 411b. Further, in the present embodiment, similarly to the tip portion 411b, the narrow portion 411c is arranged at a position slightly deviated from the center position of the electrode body 410 to the minus side in the Y-axis direction in the Y-axis direction. The narrow portion 411c can be formed by pressing the first end portion 411a of the positive electrode focusing portion 411 from both sides in the Y-axis direction.

Further, the narrow portion 411c is arranged at a position overlapping the innermost curved portion 411f, which is a curved portion of the innermost circumference of the electrode body 410, when viewed from the Y-axis direction. That is, the narrow portion 411c is arranged so that the innermost curved portion 411f is located between the recesses on both side surfaces. Specifically, the innermost curved portion 411f is arranged at a position sandwiched between the most recessed portions of the recesses on both side surfaces of the narrow portion 411c. The innermost curved portion 411f is the innermost curved portion formed when the electrode plate of the electrode body 410 is wound, that is, the curve on the plus side in the Z-axis direction formed by the innermost electrode plate. It is a part.

The joint portion 411d is arranged below the narrow portion 411c (minus side in the Z-axis direction) so as to be connected to the lower end of the narrow portion 411c. That is, the joint portion 411d is arranged at a position where the narrow portion 411c is sandwiched between the joint portion 411b and the tip portion 411b. In other words, the joint portion 411d is arranged between the first end portion 411a and the second end portion 411e. Further, the joint portion 411d is a portion to be joined to the electrode connection portions 520 and 530, and the electrode connection portion 520 is joined to the side surface of the joint portion 411d on the negative side in the Y-axis direction, and the joint portion 411d is on the positive side in the Y-axis direction. The electrode connection portion 530 is joined to the side surface of the. That is, the joint portion 411d is divided into a focusing portion on the minus side in the Y-axis direction and a focusing portion on the plus side, and the electrode connecting portion 520 is joined to the focusing portion on the minus side in the Y-axis direction, so that the focusing portion on the plus side in the Y-axis direction is joined. The electrode connecting portion 530 is joined to the focusing portion.

In this way, the joint portion 411d is arranged in a wide portion (a portion corresponding to the width W2 in FIG. 5) on the side opposite to the terminal connection portion 510 in the space between the electrode connection portions 520 and 530. There is. That is, the tip portion 411b is arranged at a position corresponding to the wide portion between the electrode connecting portions 520 and 530, and in the present embodiment, the Y axis is the same as the tip portion 411b and the narrow portion 411c. In the direction, it is arranged at a position slightly deviated from the center position of the electrode body 410 toward the minus side in the Y-axis direction.

Here, the joint portion 411d is formed to have a wider width in the Y-axis direction than the narrow portion 411c. Further, the joint portion 411d is formed to have a wider width in the Y-axis direction than the tip portion 411b. The surface of the joint portion 411d to be joined to the electrode connection portions 520 and 530 is formed to be flat.

At the joint portion between the joint portion 411d and the electrode connection portions 520 and 530, a backing plate (clip) which is a flat plate-like thin plate is provided on the surface of the joint portion 411d opposite to the electrode connection portions 520 and 530. It does not matter if it is placed.

The second end portion 411e is an end portion of the positive electrode focusing portion 411 arranged on the side opposite to the terminal connecting portion 510 of the positive electrode current collector 500. That is, the second end portion 411e is an end portion on the opposite side of the first end portion 411a in the direction intersecting the winding axis direction of the positive electrode focusing portion 411, and the joint portion 411d is formed with the first end portion 411a. It is placed in a sandwiching position. Further, the second end portion 411e is formed to be wider than the first end portion 411a (tip portion 411b, narrow portion 411c) and the joint portion 411d in the Y-axis direction. Further, the second end portion 411e has an outer edge formed by a gentle curve in a cross section when cut in a YZ plane. That is, the second end portion 411e is formed with a curved surface whose side surface is gentle.

Further, the second end portion 411e is formed so that the maximum width in the Y-axis direction is wider than the distance between the electrode connecting portion 520 and the electrode connecting portion 530 of the positive electrode current collector 500. Specifically, in the second end portion 411e, the maximum distance (width W3 in FIG. 8) between the outer surface on the positive side in the Y-axis direction and the outer surface on the negative side in the Y-axis direction in the Y-axis direction is the electrode connection portion. It is formed to be larger than the distance (W1 or W2 in FIG. 5) between the inner surface of the 520 (the surface on the positive side in the Y-axis direction) and the inner surface of the electrode connecting portion 530 (the surface on the negative side in the Y-axis direction). In other words, the distance between the electrode connecting portion 520 and the electrode connecting portion 530 of the positive electrode current collector 500 is narrower than the maximum width of the electrode body 410 in the Y-axis direction. That is, the distance between the pair of legs of the positive electrode current collector 500 is the maximum width in the portion of the positive electrode focusing portion 411 that is not fixed to the legs of the positive electrode current collector 500 (second end portion 411e). Narrower than. In the present embodiment, the maximum distance between the pair of legs of the positive electrode current collector 500 is narrower than the maximum width of the electrode body 410 in the Y-axis direction.

With the above configuration, the positive electrode focusing portion 411 has a shape in which the outer edge gradually expands from the lower end portion of the arc shape at the first end portion 411a (a shape in which a circular shape and a trapezoidal portion are connected). The joint portion 411d has a linear shape, and the second end portion 411e has a substantially oval shape in which the width becomes wider as it approaches the end portion.

Here, the narrow portion 411c is an example of a second portion having a width narrower in the Y-axis direction (second direction) than the tip portion 411b. That is, the positive electrode focusing portion 411 (first part) has a narrow portion 411c (second part) whose width in the Y-axis direction (second direction) is narrower than that of the tip portion 411b in the Z-axis direction (first direction). It has a formed first end portion 411a. Further, the joint portion 411d is arranged at a position sandwiching the narrow portion 411c (second portion) with the tip portion 411b, and the width in the Y-axis direction (second direction) is larger than that of the narrow portion 411c (second portion). This is an example of a wide third part.

The positive electrode focusing portion 421 of the electrode body 420 is arranged at a position corresponding to the electrode connecting portions 540 and 550. That is, the positive electrode focusing portion 421 has a shape symmetrical with the positive electrode focusing portion 411 of the electrode body 410 in the Y-axis direction. Further, the negative electrode focusing portions 412 and 422 have a shape symmetrical with the positive electrode focusing portions 411 and 421 in the X-axis direction.

Further, the power storage element 10 having such a configuration can be manufactured as follows. That is, first, the positive electrode focusing portion 411 having the first end portion 411a of the electrode body 410 is pressed in the Y-axis direction to the first end portion 411a in the Z-axis direction than the tip portion 411b of the positive electrode focusing portion 411. A narrow portion 411c having a narrow width in the Y-axis direction is formed (second portion forming step).

Specifically, a jig having a convex portion sandwiches the first end portion 411a of the positive electrode focusing portion 411 from both sides in the Y-axis direction. Then, by pressing (pressing) the first end portion 411a from both sides in the Y-axis direction with the jig, the first end portion 411a is recessed to form the narrow portion 411c.

Then, the positive electrode focusing portion 411 is arranged between the electrode connecting portions 520 and 530 (first part arrangement step). Specifically, the positive electrode focusing portion 411 is inserted between the electrode connecting portions 520 and 530 with the first end portion 411a sandwiched between the jigs. Then, the jig is pulled out.

Then, the positive electrode focusing portion 411 and the electrode connecting portions 520 and 530 are joined (joining step). Specifically, the joint portion 411d of the positive electrode focusing portion 411 and the electrode connection portions 520 and 530 are joined by welding or the like. The same applies to the electrode body 420.

As described above, according to the power storage element 10 according to the embodiment of the present invention, the electrode body 410 is the first of the positive electrode focusing portions 411 arranged between the electrode connecting portions 520 and 530 of the positive electrode current collector 500. A narrow portion 411c having a width narrower than that of the tip portion 411b is formed at one end portion 411a. That is, since the narrow narrow portion 411c is formed in the first end portion 411a, the width of the entire first end portion 411a can be narrowed. As a result, when the positive electrode focusing portion 411 is inserted between the electrode connecting portions 520 and 530, the first end portion 411a is suppressed from being caught by the electrode connecting portion 520 or 530, and the positive electrode focusing portion 411 is inserted into the electrode connecting portion 520. It can be easily inserted between 530. Therefore, in the power storage element 10, it is possible to prevent the electrode body 410 from being damaged when the electrode body 410 and the positive electrode current collector 500 are connected to each other.

If the tip portion 411b is formed thin in order to narrow the width of the first end portion 411a, the tip portion 411b becomes a sharp shape, and sharp wrinkles (sharp edges) may occur in the tip portion 411b. In this case, the sharp edge may break through the separator and cause a short circuit between the positive electrode and the negative electrode of the electrode body 410. On the other hand, in the power storage element 10 of the present embodiment, since the tip portion 411b has a rounded shape, the occurrence of sharp edges can be suppressed and the occurrence of short circuits can be suppressed.

In the power storage element 10, since the side surface of the narrow portion 411c is formed with a curved surface, it is possible to suppress the occurrence of a sharp edge in the electrode body 410, and it is possible to suppress the occurrence of a short circuit.

In the electrode body 410, since the narrow portion 411c has a shape in which both side surfaces are recessed, it is sufficient to recess the first end portion 411a from both sides to form the narrow portion 411c, and the width is easily narrowed. Part 411c can be formed.

The distance between the pair of legs of the positive electrode current collector 500 is narrower than the maximum width of the electrode body 410, but the electrode body 410 has the narrow portion 411c, so that the pair The positive electrode focusing portion 411 can be easily inserted between the legs of the.

The positive electrode current collector 500 has a configuration in which the gap on the terminal connection portion 510 side is narrowed among the gaps between the electrode connection portions 520 and 530, and the narrow portion 411c of the electrode body 410 is the positive electrode focusing portion 411. It is formed on the first end portion 411a on the terminal connection portion 510 side. As a result, even in the positive electrode current collector 500 having a narrow gap on the terminal connection portion 510 side, the positive electrode focusing portion 411 of the electrode body 410 can be easily inserted between the electrode connection portions 520 and 530. Therefore, in the power storage element 10, it is possible to prevent the electrode body 410 from being damaged when the electrode body 410 and the positive electrode current collector 500 are connected to each other.

In the electrode body 410, the positive electrode focusing portion 411 has a joint portion 411d wider than the narrow portion 411c at a position where the narrow portion 411c is sandwiched between the tip portion 411b and the tip portion 411b. That is, since the narrow portion 411c may be formed by recessing the tip portion 411b and the joint portion 411d, the narrow portion 411c can be easily formed.

In the electrode body 410, the narrow portion 411c is formed at the first end portion 411a which is the end portion in the direction intersecting the winding axis direction of the positive electrode focusing portion 411, so that the first end portion 411a is a curved portion. It has become. That is, in the winding type electrode body 410, by forming a narrow portion 411c in the curved portion to narrow the width of the curved portion, the curved portion can be easily inserted between the electrode connecting portions 520 and 530. can do. Therefore, in the power storage element 10, it is possible to prevent the electrode body 410 from being damaged when the electrode body 410 and the positive electrode current collector 500 are connected to each other.

In the electrode body 410, when the narrow portion 411c is arranged closer to the tip portion 411b than the innermost peripheral curved portion 411f when viewed from the Y-axis direction, the electrode plate is crushed when forming the narrow portion 411c. , Sharp edges may occur. Further, when the narrow portion 411c is arranged closer to the central portion of the electrode body 410 than the innermost curved portion 411f, the narrow portion 411c is formed at a portion overlapping the winding space, so that the narrow portion 411c is formed due to the repulsion of the electrode plate or the like. It becomes difficult to form the narrow portion 411c. Therefore, in the electrode body 410, the narrow portion 411c is arranged at a position overlapping the innermost curved portion 411f when viewed from the Y-axis direction, so that the sharp edge generated when the narrow portion 411c is formed is formed. It can be suppressed and the narrow portion 411c can be easily formed.

In the method for manufacturing the power storage element 10, the positive electrode focusing portion 411 of the electrode body 410 is pressed to form a narrow portion 411c at the first end portion 411a, and the positive electrode focusing portion 411 is used as a pair of legs of the positive electrode current collector 500. The positive electrode focusing portion 411 and the pair of leg portions are joined to each other. That is, by forming a narrow narrow portion 411c at the end portion of the positive electrode focusing portion 411 of the electrode body 410, the width of the entire end portion can be narrowed. As a result, it is possible to prevent the end portion of the positive electrode focusing portion 411 from being caught by the pair of legs of the positive electrode current collector 500, and the positive electrode focusing portion 411 can be easily inserted between the pair of legs to form the electrode body 410. Can be joined to the positive electrode current collector 500. Therefore, in the method of manufacturing the power storage element 10, it is possible to prevent the electrode body 410 from being damaged.

Since the negative electrode focusing portion 412 has the same configuration as the positive electrode focusing portion 411, the same effect can be obtained. Further, since the electrode body 420 has the same configuration as the electrode body 410, the same effect can be obtained.

Although the power storage element and the method for manufacturing the power storage element according to the embodiment of the present invention have been described above, the present invention is not limited to this embodiment. That is, it should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the claims rather than the above description, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

In the above embodiment, the narrow portion 411c is formed in the positive electrode focusing portion 411 arranged at the end portion of the electrode body 410 in the winding axis direction. However, the narrow portion 411c may be formed at a position (for example, a central position) different from the end portion in the winding axis direction of the electrode body 410.

In the above embodiment, the narrow side portion 411c is formed with a curved surface on the side surface, but the side surface may be formed with a flat surface.

In the above embodiment, the narrow portion 411c has a shape in which both side surfaces are recessed, but a narrow portion 411c may have a shape in which only one side is recessed.

In the above embodiment, the positive electrode current collector 500 is configured such that the space between the electrode connection portions 520 and 530 is narrower on the terminal connection portion 510 side. However, the positive electrode current collector 500 may be configured such that the space is wider on the terminal connection portion 510 side, or may be configured to have the same width.

In the above embodiment, the narrow portion 411c is formed at the end of the positive electrode focusing portion 411 on the terminal connection portion 510 side. However, the narrow portion 411c may be formed on the side to be inserted into the positive electrode focusing portion 411, and is not limited to being formed on the end portion on the terminal connection portion 510 side.

The above-described modification of the present embodiment is the same for the negative electrode focusing portion 412, and further is the same for the electrode body 420.

In the above embodiment, all of the positive electrode focusing portion 411, the negative electrode focusing portion 412, the positive electrode focusing portion 421, and the negative electrode focusing portion 422 included in the electrode bodies 410 and 420 have the above configuration. However, at least one of the positive electrode focusing unit 411, the negative electrode focusing unit 412, the positive electrode focusing unit 421, and the negative electrode focusing unit 422 may have the above configuration.

In the above embodiment, the power storage element 10 is provided with two electrode bodies 410 and 420. However, the power storage element 10 may include one electrode body or three or more electrode bodies. In this case, the current collector has a shape corresponding to the electrode body.

Further, the present invention can be realized not only as such a power storage element 10 and a method for manufacturing the same, but also as an electrode body 410, 420 included in the power storage element 10 and a method for manufacturing the same.

The present invention can be applied to a power storage element or the like that can suppress damage to the electrode body when the electrode body and the current collector are connected.

10 Power storage element 100 Container 110 Lid body 110a, 110b Through hole 111 Container body 200 Positive electrode terminal 210, 310 Shaft part 300 Negative electrode terminal 410, 420 Electrode body 411, 421 Positive electrode focusing part (Part 1)
411a First end 411b Tip 411c Narrow part (second part)
411d Joint (Part 3)
411e Second end 411f Innermost curved part 412, 422 Negative electrode focusing part (Part 1)
500 Positive electrode current collector 510 Terminal connection (connection)
511, 611 Openings 520, 530, 540, 550 Electrode connection (legs)
600 Negative current collector

Claims (9)

Winding type electrode body and
A current collector connected to the electrode body is provided.
The current collector has a terminal connection portion and a pair of legs extending in a first direction from the terminal connection portion and arranged in a second direction orthogonal to the first direction.
The electrode body has a first portion arranged between the pair of legs.
The first section, in the first direction, possess a distal end facing the terminal connecting portion, and said distal second portion narrower the second width than portion,
The second part is a power storage element arranged at a position biased toward the tip end side of the electrode body in the first direction. Winding type electrode body and
A current collector connected to the electrode body is provided.
The current collector has a terminal connection portion and a pair of legs extending in a first direction from the terminal connection portion and arranged in a second direction orthogonal to the first direction.
The electrode body has a first portion arranged between the pair of legs.
The first section, in the first direction, possess a distal end facing the terminal connecting portion, and said distal second portion narrower the second width than portion,
The first part has a third part which is a portion to be joined to the pair of legs at a position where the second part is sandwiched between the tip part and the tip part.
The third part is a power storage element having a width wider in the second direction than the second part. Winding type electrode body and
A current collector connected to the electrode body is provided.
The current collector has a terminal connection portion and a pair of legs extending in a first direction from the terminal connection portion and arranged in a second direction orthogonal to the first direction.
The electrode body has a first portion arranged between the pair of legs.
The first section, in the first direction, possess a distal end facing the terminal connecting portion, and said distal second portion narrower the second width than portion,
The portion of the second portion having the narrowest width in the second direction is a power storage element arranged at a position overlapping the curved portion of the innermost circumference of the electrode body when viewed from the second direction. The power storage element according to any one of claims 1 to 3, wherein the second part is a curved surface on a side surface in the second direction. The power storage element according to any one of claims 1 to 4, wherein the second part has a shape in which both side surfaces in the second direction are recessed. The power storage element according to any one of claims 1 to 5 , wherein the distance between the pair of legs is narrower than the maximum width of the electrode body in the second direction. The current collector further has a connecting portion that connects the pair of legs.
The pair of legs are arranged so that the space between the pair of legs is narrower on the connecting portion side.
The power storage element according to any one of claims 1 to 6 , wherein the second part is formed at an end portion of the first part on the connecting portion side. A method for manufacturing a power storage element including an electrode body and a current collector connected to the electrode body and having a pair of legs extending in the first direction and lining up in the second direction.
A first portion having an end portion of the electrode body is pressed in the second direction, and the width of the end portion in the first direction is narrower than that of the tip portion of the first portion in the second direction. The second part forming process to form two parts and
The first part arranging step of arranging the first part between the pair of legs, and
Including a joining step of joining the first part and the pair of legs.
In the second part forming step, the second part is arranged at a position biased toward the tip end side of the electrode body in the first direction.
Manufacturing method of a charge reservoir element. A method for manufacturing a power storage element including an electrode body and a current collector connected to the electrode body and having a pair of legs extending in the first direction and lining up in the second direction.
A first portion having an end portion of the electrode body is pressed in the second direction, and the width of the end portion in the first direction is narrower than that of the tip portion of the first portion in the second direction. The second part forming process to form two parts and
The first part arranging step of arranging the first part between the pair of legs, and
Including a joining step of joining the first part and the pair of legs.
In the joining step, the third part is a portion to be joined to the pair of legs at a position where the second part is sandwiched between the tip and the tip of the first part, and is more than the second part. Place a third part that is wide in the second direction
Manufacturing method of a charge reservoir element.

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