JP7273554B2 - sealed battery - Google Patents

Description

In the present invention, an electrode body in which a sheet-like positive electrode, a negative electrode, and a separator are laminated in the thickness direction and wound, and an insulating plate positioned in the axial direction of the electrode body are accommodated in a battery case. It relates to a sealed battery.

A sealed battery in which a sheet-shaped positive electrode, a negative electrode, and a separator are laminated in the thickness direction and wound, and an insulating plate positioned in the axial direction of the electrode body is housed in a battery case. Are known. In such a sealed battery, for example, as disclosed in Patent Document 1, a battery element obtained by stacking a positive electrode and a negative electrode in a rectangular battery can with a separator interposed therebetween and then flatly winding them. is housed therein, and the battery can is sealed with a lid. An upper insulating plate is arranged between the battery element and the lid to prevent a short circuit.

The upper insulating plate is a plate-like member elongated in one direction when viewed from the thickness direction. The upper insulating plate has a plate-like portion and a convex side wall provided on the peripheral edge of the plate-like portion.

JP 2007-188711 A

By the way, when an impact is applied to the sealed battery having the above-described structure, the battery element (hereinafter referred to as the electrode body) and the upper insulating plate (hereinafter referred to as the insulating plate) are subjected to impact through the battery can (hereinafter referred to as the battery case). Adds a shock.

Here, since the electrode body is wound in an elliptical shape around the axis, the rigidity of both ends of the electrode body in the long-axis direction is higher than the rigidity of the other parts when viewed in the axial direction. In addition, the insulating plate has a convex side wall (hereinafter referred to as a rib) provided on the periphery of the plate-like portion, so that the rigidity of the periphery is higher than that of the other portions.

Therefore, when a strong impact is repeatedly applied to the electrode body and the insulating plate, if the longitudinal end of the electrode body repeatedly contacts the insulating plate, there is a possibility that the insulating plate will be dented at a portion other than the peripheral edge. be. Then, the deformed insulating plate may also deform the electrode assembly.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sealed battery having an insulating plate that is resistant to deformation even when a strong impact is repeatedly applied to the sealed battery.

A sealed battery according to an embodiment of the present invention includes an electrode assembly in which a sheet-shaped positive electrode, a negative electrode, and a separator are laminated in the thickness direction, and an electrode body wound in an elliptical shape around the axis, and an insulating plate positioned in the axial direction with respect to the electrode body so as to coincide with the axial direction of the electrode body, the insulating plate being longer in the long axis direction than the length in the short axis direction of the electrode body when viewed from the axial direction; and a battery case in which the electrode body and the insulating plate are housed. The insulating plate has a flat plate portion and an outer peripheral rib positioned on the outer peripheral edge of the flat plate portion and extending in the thickness direction. At both ends in the longitudinal direction of the flat plate portion, rigidity higher than the other portions of the flat plate portion is provided at positions at least partially overlapping with ends in the longitudinal direction of the electrode body when viewed from the axial direction. is provided (first configuration).

As a result, when the sealed battery receives a strong impact, it is possible to suppress deformation of the insulating plate other than the outer peripheral ribs due to the elliptical electrode body when viewed from the axial direction. That is, at both ends of the flat plate portion of the insulating plate in the longitudinal direction, other electrodes of the flat plate portion are provided at positions at least partially overlapping with the ends of the electrode body in the longitudinal direction when viewed from the axial direction. Since the high-rigidity portion having a rigidity higher than that of the portion is provided, deformation of the insulating plate is suppressed even when the electrode body repeatedly contacts the insulating plate due to repeated impacts on the sealed battery. .

Therefore, deformation of the insulating plate can be suppressed, and deformation of the electrode body due to the deformed insulating plate can be suppressed.

In the first configuration, the high-rigidity portions are provided at both ends of the flat plate portion in the longitudinal direction in a range that overlaps the ends of the electrode body in the longitudinal direction when viewed from the axial direction (first configuration). 2 configuration).

Thereby, the high-rigidity portion of the insulating plate is positioned with respect to the electrode body so as to cover the ends of the electrode body in the longitudinal direction when viewed from the axial direction of the electrode body. Therefore, even if the sealed battery receives repeated impacts and the ends of the electrode bodies in the longitudinal direction repeatedly contact the insulating plate, deformation of the insulating plate can be suppressed more reliably.

In the first or second configuration, the high-rigidity portion is a thick portion that is thicker than other portions of the flat plate portion (third configuration). As a result, it is possible to increase the rigidity of the portions of the insulating plate that overlap the ends of the electrode body in the longitudinal direction when viewed from the axial direction. Therefore, deformation of the insulating plate can be suppressed even when the electrode body repeatedly contacts the insulating plate due to repeated strong impacts on the sealed battery.

In the third configuration, the thick portion protrudes from the other portion of the flat plate portion on the side opposite to the electrode body (fourth configuration). As a result, the thick portion does not protrude toward the electrode body side of the flat plate portion, so that the configuration of the sealed battery can be made compact.

In the first or second configuration, the high rigidity portion has a first rib extending in the longitudinal direction (fifth configuration). As a result, it is possible to increase the rigidity of the portions of the insulating plate that overlap the ends of the electrode body in the longitudinal direction when viewed from the axial direction. Therefore, deformation of the insulating plate can be suppressed even when the electrode body repeatedly contacts the insulating plate due to repeated strong impacts on the sealed battery.

In the fifth configuration, the high-rigidity portion has second ribs that cross the first ribs when viewed in the thickness direction (sixth configuration).

As a result, in the rigidity of both longitudinal ends of the insulating plate, the rigidity of the portions overlapping the longitudinal ends of the electrode body when viewed from the axial direction can be further increased. Therefore, even if the sealed battery is repeatedly subjected to strong impacts and the electrode body repeatedly contacts the insulating plate, deformation of the insulating plate can be suppressed more reliably.

In the sixth configuration, the first rib and the second rib are provided on a surface of the flat plate portion opposite to the electrode body (seventh configuration). As a result, the first rib does not protrude toward the electrode body of the flat plate portion, so that the configuration of the sealed battery can be made compact.

According to the sealed battery according to one embodiment of the present invention, both ends of the flat plate portion of the insulating plate in the longitudinal direction overlap at least a part of the ends of the electrode body in the longitudinal direction when viewed from the axial direction. A high-rigidity portion having a rigidity higher than that of other portions of the flat plate portion is provided at the position. As a result, deformation of the insulating plate can be suppressed, so that deformation of the electrode body due to the deformed insulating plate can be suppressed.

FIG. 1 is a perspective view showing a schematic configuration of a sealed battery according to Embodiment 1 of the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a perspective view showing a schematic configuration of an electrode body. FIG. 4 is a perspective view showing a schematic configuration of an upper insulating plate. 5 is a cross-sectional view taken along the line VV in FIG. 4. FIG. FIG. 6 is a diagram schematically showing the relationship between an upper insulating plate and an electrode assembly when a conventional sealed battery provided with an upper insulating plate receives an impact. FIG. 7 is a perspective view schematically showing the positional relationship between the upper insulating plate and the electrode body. FIG. 8 is a plan view of part of the upper insulating plate. 9 is a perspective view showing a schematic configuration of an upper insulating plate of a sealed battery according to Embodiment 2. FIG. FIG. 10 is a plan view of part of the upper insulating plate.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same reference numerals are given to the same or corresponding parts in the drawings, and the description thereof will not be repeated.

<Embodiment 1>
(overall structure)
FIG. 1 is a perspective view showing a schematic configuration of a sealed battery 1 according to Embodiment 1 of the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. 1 and 2, the configuration of the sealed battery 1 is shown in a simplified manner for the sake of explanation.

The sealed battery 1 includes a bottomed cylindrical outer can 10 , a cover plate 20 covering an opening of the outer can 10 , an electrode body 30 , an upper insulating plate 40 (insulating plate), and a bottom insulator 50 . It has

The electrode body 30 , the upper insulating plate 40 and the bottom insulator 50 are housed inside the outer can 10 . By welding the opening of the outer can 10 to the outer periphery of the cover plate 20 with the opening of the outer can 10 covered by the cover plate 20, the columnar battery case 2 having a space inside is constructed. The battery case 2 is formed in a flat shape in which the dimension in the width direction (horizontal direction in FIG. 1) is larger than the dimension in the thickness direction (direction on the paper surface of FIG. 1).

In addition to the electrode assembly 30, the upper insulating plate 40 and the bottom insulator 50, the battery case 2 contains a connection plate 27 electrically connected to the electrode assembly 30 and a non-aqueous electrolyte (hereinafter simply referred to as the electrolyte). ) etc. are also enclosed.

FIG. 3 is a perspective view showing a schematic configuration of the electrode assembly 30. As shown in FIG. The electrode body 30 is formed by stacking a sheet-shaped positive electrode 31 and a negative electrode 32, for example, so that a separator 33 is positioned between them, and spirally formed as shown in FIGS. It is a wound electrode body formed by winding. Specifically, the electrode body 30 is formed by stacking the positive electrode 31, the negative electrode 32, and the separator 33 in the thickness direction, winding them around the axis P, and then crushing them into a flat shape. That is, the electrode body 30 is a wound electrode body in which the positive electrode 31, the negative electrode 32, and the separator 33 are wound around the axis P in an elliptical shape.

As shown in FIG. 3, the electrode body 30 has rounded portions 30a at both ends in the longitudinal direction when viewed from the axial direction. The R portion 30a is a portion where the positive electrode 31, the negative electrode 32, and the separator 33, which are formed in a sheet shape, are bent in a U shape in a state in which they are superimposed in the thickness direction. Therefore, the rigidity in the axial direction of the R portion 30 a is higher than the rigidity in the axial direction of other portions of the electrode body 30 .

Here, in FIG. 2, only several layers on the outer peripheral side of the electrode body 30 are illustrated. However, FIG. 2 only omits illustration of the inner peripheral side portion of the electrode body 30, and naturally, the positive electrode 31, the negative electrode 32, and the separator 33 are also present on the inner peripheral side of the electrode body 30. .

The positive electrode 31 is obtained by providing positive electrode active material layers containing a positive electrode active material on both sides of a positive electrode current collector made of a metal foil such as aluminum. Specifically, the positive electrode 31 is formed by coating a positive electrode mixture containing a positive electrode active material, which is a lithium-containing oxide capable of intercalating and deintercalating lithium ions, a conductive aid, a binder, etc., onto a positive electrode current collector made of aluminum foil or the like. It is formed by drying with Examples of the lithium-containing oxide that is the positive electrode active material include lithium cobalt oxides such as LiCoO ₂ , lithium manganese oxides such as LiMn ₂ O ₄ , and lithium composite oxides such as lithium nickel oxides such as LiNiO ₂ . is preferred. As the positive electrode active material, only one kind of substance may be used, or two or more kinds of substances may be used. Moreover, the positive electrode active material is not limited to the above substances.

The negative electrode 32 is obtained by providing negative electrode active material layers containing a negative electrode active material on both sides of a negative electrode current collector made of metal foil such as copper. Specifically, the negative electrode 32 is formed by coating a negative electrode mixture containing a negative electrode active material capable of intercalating and deintercalating lithium ions, a conductive aid, a binder, etc. on a negative electrode current collector made of copper foil or the like, and drying it. It is formed. As the negative electrode active material, for example, it is preferable to use a carbon material capable of intercalating and deintercalating lithium ions (graphites, pyrolytic carbons, cokes, vitreous carbons, etc.). The negative electrode active material is not limited to the above substances.

A positive electrode lead 34 is connected to the positive electrode 31 of the electrode body 30 , while a negative electrode lead 35 is connected to the negative electrode 32 . Thereby, the positive electrode lead 34 and the negative electrode lead 35 are pulled out of the electrode assembly 30 . The tip side of the positive electrode lead 34 is connected to the cover plate 20 . On the other hand, the tip side of the negative lead 35 is connected to the negative terminal 22 through the connection plate 27 as will be described later.

The outer can 10 is a bottomed cylindrical member made of aluminum alloy, and constitutes the battery case 2 together with the cover plate 20 . As shown in FIG. 1, the outer can 10 is a bottomed tubular member having a rectangular bottom surface 11 with arcuate short sides. Specifically, the outer can 10 has a bottom surface 11 and a flat cylindrical side wall 12 having a smooth curved surface. That is, the outer can 10 is formed in a flat shape so that the dimension in the thickness direction corresponding to the short side direction of the bottom surface 11 is smaller than the width direction dimension corresponding to the long side direction of the bottom surface 11 . Moreover, since the outer can 10 is joined to a lid plate 20 connected to a positive electrode lead 34 as will be described later, it also serves as a positive electrode terminal of the sealed battery 1 .

As shown in FIG. 2, a polyethylene sheet for preventing a short circuit between the positive electrode 31 and the negative electrode 32 of the electrode assembly 30 through the outer can 10 is attached to the inner bottom of the outer can 10. A bottom insulator 50 is disposed. The electrode body 30 described above is arranged such that one end is positioned on the bottom insulator 50 .

An upper insulating plate 40 is arranged on the opening side of the outer can 10, that is, on the side of the cover plate 20 to prevent a short circuit from occurring between the electrode body 30 and the cover plate 20 and the negative electrode terminal 22, respectively. . The upper insulating plate 40 is arranged so as to cover the cover plate 20 side of the electrode assembly 30 . The upper insulating plate 40 is formed with a through hole 40a through which the negative electrode lead 35 passes.

A detailed configuration of the upper insulating plate 40 will be described later.

The cover plate 20 covers the opening of the outer can 10 and has its outer peripheral portion connected to the opening of the outer can 10 by welding. Like the outer can 10, the cover plate 20 is made of an aluminum alloy member, and has a rectangular short side formed in an arc so that it can be fitted inside the opening of the outer can 10. As shown in FIG.

The cover plate 20 has a through hole 20a formed in the central portion in the longitudinal direction thereof, and a splitting vent 23 and an injection port 24 are formed in the longitudinal direction of the cover plate 20 across the through hole 20a. That is, the cover plate 20 is provided with the cleavage vent 23 , the through hole 20 a and the injection port 24 arranged side by side in the longitudinal direction of the cover plate 20 .

As shown in FIG. 2, an insulating packing 21 made of polypropylene and a negative electrode terminal 22 made of stainless steel are inserted into the through hole 20a of the cover plate 20. As shown in FIG. Specifically, a substantially cylindrical insulating packing 21 through which a substantially columnar negative terminal 22 is inserted is fitted to the periphery of the through hole 20a.

The negative electrode terminal 22 has a configuration in which flat portions are integrally formed at both ends of a cylindrical shaft portion. The negative terminal 22 is arranged with respect to the insulating packing 21 such that the planar portion is exposed to the outside while the shaft portion is positioned within the insulating packing 21 .

The negative electrode terminal 22 is electrically connected to the connection plate 27 by penetrating the connection plate 27 made of nickel. The connection plate 27 is a rectangular plate member, and is connected to the negative electrode terminal 22 so as to extend in the longitudinal direction of the cover plate 20 , that is, from the negative electrode terminal 22 toward the cleavage vent 23 . Thus, the negative terminal 22 is electrically connected to the negative electrode 32 of the electrode body 30 via the connection plate 27 and the negative lead 35 .

Between the connecting plate 27 and the cover plate 20, a terminal insulating plate 26 having a rectangular shape in a plan view is arranged for electrically insulating the two. Similar to the connection plate 27 , the terminal insulating plate 26 is penetrated by the shaft portion of the negative terminal 22 and is arranged to extend toward the splitting vent 23 . That is, the shaft portion of the negative electrode terminal 22 passes through the cover plate 20 as well as through the terminal insulating plate 26 and the connection plate 27 .

An injection port 24 formed in the cover plate 20 is a through hole for injecting an electrolytic solution into the battery case 2 . The injection port 24 is formed in a substantially circular shape in plan view. The injection port 24 is sealed by a sealing plug 25 having a T-shaped cross section, as shown in FIG. The peripheral portion of the brim portion of the sealing plug 25 and the cover plate 20 are arranged so that a gap does not occur between the peripheral portion of the sealing plug 25 and the inlet 24 after the electrolytic solution is injected into the battery case 2 . are joined by laser welding.

As shown in FIG. 1 , the splitting vent 23 is formed in an oval shape elongated in the longitudinal direction of the cover plate 20 when viewed from the top of the cover plate 20 , that is, when the battery case 2 is viewed from above. As shown in FIG. 2, the cleaving vent 23 includes a thin valve body 23a that is oval in plan view and has a thickness smaller than the thickness of other portions of the cover plate 20, and a thin valve body 23a that surrounds the outer periphery of the thin valve body 23a. and a thin portion 23 b provided with a groove on the upper surface side of the cover plate 20 .

As described above, by providing the thin portion 23b so as to surround the thin valve body 23a, when the pressure inside the battery case 2 rises, the deformation of the battery case 2 due to the rise in the internal pressure of the battery case 2 and the internal pressure, The thin portion 23b having the smallest thickness in the cover plate 20 is broken. As a result, the thin valve body 23a is pushed upward with respect to the cover plate 20, so that gas and the like in the battery case 2 are released to the outside. Thereby, it is possible to prevent the battery case 2 from being damaged due to an increase in internal pressure.

(upper insulating plate)
Next, the configuration of the upper insulating plate 40 that electrically insulates the electrode body 30 and the cover plate 20 will be described in detail with reference to FIGS. 2, 4, 5, 7 and 8. FIG. FIG. 4 is a perspective view showing a schematic configuration of the upper insulating plate 40. As shown in FIG. 5 is a cross-sectional view taken along the line VV in FIG. 4. FIG. FIG. 7 is a perspective view showing a state in which the upper insulating plate 40 is arranged so that the thickness direction of the electrode body 30 is aligned with the axial direction. 8 is a plan view of part of the upper insulating plate 40 including the thick portion 43. FIG. In FIG. 8, the outline of the electrode body 30 is indicated by a dashed line for explanation.

As shown in FIGS. 4 and 7, the upper insulating plate 40 is a plate-like member in which the short sides of a rectangle are arc-shaped in plan view. The upper insulating plate 40 has a plate-shaped bottom plate portion 41 (flat plate portion) and an outer peripheral rib 42 located on the outer peripheral edge of the bottom plate portion 41 and extending in the thickness direction of the bottom plate portion 41 . 4 and 5, reference numeral 44 denotes a rib extending in the lateral direction of the upper insulating plate 40. As shown in FIG.

As shown in FIGS. 4 and 7, the bottom plate portion 41 has a rectangular short side that is arc-shaped in plan view. As shown in FIGS. 2 and 7 , the bottom plate portion 41 is positioned in the battery case 2 of the sealed battery 1 in the axial direction with respect to the electrode assembly 30 . That is, the upper insulating plate 40 is positioned in the axial direction with respect to the electrode body 30 so that the thickness direction coincides with the axial direction of the electrode body 30 . The upper insulating plate 40 is longer in the long axis direction than the short axis direction of the electrode body 30 when viewed from the axial direction.

The bottom plate portion 41 is provided with a plurality of holes 41a arranged in the longitudinal direction. By providing the hole portion 41 a in the bottom plate portion 41 , when the electrolytic solution is injected into the battery case 2 from the inlet 24 , the electrolytic solution passes through the hole portion 41 a of the upper insulating plate 40 and enters the battery case 2 . Efficiently filled.

As shown in FIGS. 4 to 7, the bottom plate portion 41 has thick portions 43 (high-rigidity portions) at both ends in the longitudinal direction, which are thicker than other portions. The thick portion 43 protrudes from the other portion of the bottom plate portion 41 on the side opposite to the electrode body 30, that is, in the protruding direction of the outer peripheral rib 42, which will be described later. This allows the sealed battery 1 to have a compact configuration. The thick portion 43 has higher rigidity than other portions of the bottom plate portion 41 of the upper insulating plate 40 .

As shown in FIGS. 7 and 8 , in the sealed battery 1 , the thick portion 43 is the portion of the bottom plate portion 41 of the upper insulating plate 40 when viewed from the axial direction of the electrode body 30 . It is formed in a range overlapping with the R portions 30a located at both ends of the body 30 in the longitudinal direction. When the upper insulating plate 40 is viewed from the axial direction of the electrode body 30, the range in which the bottom plate portion 41 of the upper insulating plate 40 overlaps the R portion 30a includes the entire overlapping range. Therefore, in the bottom plate portion 41 of the upper insulating plate 40, a thick portion 43 is provided in a range overlapping with the R portion 30a when viewed from the axial direction of the electrode body 30. As shown in FIG.

In this embodiment, the thickness of the thick portion 43 is constant in the longitudinal direction and the lateral direction. The thickness of the thick portion 43 may vary in at least one of the longitudinal direction and the lateral direction of the upper insulating plate 40 .

As shown in FIGS. 4, 5, 7 and 8, the outer peripheral rib 42 is provided on the outer peripheral side of the bottom plate portion 41 so as to surround the bottom plate portion 41 when viewed from the thickness direction of the bottom plate portion 41. . The outer peripheral rib 42 protrudes outward in the thickness direction from one surface of the bottom plate portion 41 . The one surface is the surface of the upper insulating plate 40 located on the lid plate 20 side when the upper insulating plate 40 is arranged in the battery case 2 in the axial direction with respect to the electrode assembly 30 .

The above-described outer peripheral rib 42 can secure a distance necessary for electrical insulation between the electrode body 30 and the cover plate 20 and protect the positive electrode lead 34 and the negative electrode lead 35 within the battery case 2 .

By the way, if the sealed battery receives a shock at the corner portion as indicated by the hatched arrow in FIG. Force is input from 30 . The upper insulating plate X is a conventional upper insulating plate in which the bottom plate portion is not provided with a thick portion as in the present embodiment. Note that the conventional sealed battery has the same configuration as the sealed battery 1 of the present embodiment except for the upper insulating plate. Therefore, in FIG. 6, the components of the conventional sealed battery other than the upper insulating plate are denoted by the same reference numerals as those of the sealed battery 1 of the present embodiment.

In the upper insulating plate X, the rigidity in the thickness direction on the outer peripheral side of the bottom plate portion Xa provided with the outer circumferential rib Xb is higher than the rigidity in the thickness direction at other portions. Therefore, when a large force is applied to the bottom plate portion Xa in the thickness direction, portions other than the outer peripheral rib Xb may be deformed in the thickness direction, as shown in FIG.

Further, as described above, the electrode body 30 wound in an elliptical shape when viewed from the axial direction has high rigidity in the axial direction at the R portions 30a located at both ends in the longitudinal direction when viewed from the axial direction. . Therefore, when the sealed battery is subjected to repeated strong impacts, if the R portion 30a of the electrode body 30 repeatedly contacts the bottom plate portion Xa of the upper insulating plate X, the bottom plate portion Xa may be deformed in the thickness direction. Then, as shown in FIG. 6, the electrode body 30 positioned in the axial direction with respect to the bottom plate portion Xa of the upper insulating plate X may be deformed by the deformed bottom plate portion Xa.

In contrast, in the present embodiment, the upper insulating plate 40 has thick portions 43 at both ends in the longitudinal direction. As described above, in the sealed battery 1 , the thick portion 43 is the length of the electrode body 30 in the bottom plate portion 41 of the upper insulating plate 40 when the upper insulating plate 40 is viewed from the axial direction of the electrode body 30 . It is formed in a range overlapping with the R portions 30a located at both ends in the axial direction.

Thereby, the rigidity in the thickness direction can be improved at both ends in the longitudinal direction of the upper insulating plate 40 . Therefore, when the sealed battery 1 is repeatedly subjected to a strong impact such as being dropped, the bottom plate portion 41 of the upper insulating plate 40 is positioned at both ends in the longitudinal direction of the electrode assembly 30 as indicated by the white arrows in FIG. Deformation of the bottom plate portion 41 can be suppressed even when a force is repeatedly applied from the portion 30a. Therefore, deformation of the electrode body 30 due to the deformed bottom plate portion 41 of the upper insulating plate 40 can be suppressed.

<Embodiment 2>
FIG. 9 shows a schematic configuration of the upper insulating plate 140 of the sealed battery according to Embodiment 2. As shown in FIG. The upper insulating plate 140 of this embodiment differs from the upper insulating plate 40 of the first embodiment in that it has a high rigidity portion 143 including first ribs 144 and second ribs 145 instead of the thick portion 43 . In the following, configurations similar to those of the first embodiment are denoted by the same reference numerals, descriptions thereof are omitted, and only configurations different from the first embodiment are described.

As shown in FIG. 9 , the upper insulating plate 140 is positioned at the bottom plate portion 41 , the outer peripheral ribs 42 , and both ends in the longitudinal direction of the bottom plate portion 41 , and has a high rigidity that is higher than the other portions of the bottom plate portion 41 . and a portion 143 . High-rigidity portion 143 has first ribs 144 extending in the longitudinal direction of upper insulating plate 140 and second ribs 145 extending in the lateral direction of upper insulating plate 140 . The first rib 144 and the second rib 145 intersect when viewed from the thickness direction of the upper insulating plate 140 . The first rib 144 and the second rib 145 are provided on the surface of the bottom plate portion 41 opposite to the electrode body 30 , that is, the surface on which the outer peripheral rib 42 is located. This allows the sealed battery to have a compact configuration.

FIG. 10 is a plan view of a portion of upper insulating plate 140 including high-rigidity portion 143. FIG. In FIG. 10, the outline of the electrode body 30 is indicated by a dashed line for explanation.

As shown in FIG. 10, in the sealed battery 1, the high-rigidity portion 143 is formed by viewing the upper insulating plate 140 from the axial direction of the electrode assembly 30, similarly to the thick portion 43 of the first embodiment. of the bottom plate portion 41 overlaps with the R portions 30a located at both ends of the electrode body 30 in the long axis direction. That is, the first ribs 144 and the second ribs 145 of the high-rigidity portion 143 are formed at both ends in the longitudinal direction of the electrode body 30 in the upper insulating plate 140 when the upper insulating plate 140 is viewed from the axial direction of the electrode body 30 . It is formed in a range overlapping with the located R portion 30a.

Thereby, the rigidity in the thickness direction can be improved at both ends in the longitudinal direction of the upper insulating plate 140 . Therefore, even if the sealed battery 1 is repeatedly subjected to a strong impact such as being dropped, and the R portions 30a located at both ends in the long axis direction of the electrode assembly 30 repeatedly contact the bottom plate portion 41 of the upper insulating plate 140, the bottom plate will remain intact. Deformation of the portion 41 can be suppressed. Therefore, deformation of the electrode body 30 due to the deformed bottom plate portion 41 of the upper insulating plate 140 can be suppressed.

In this embodiment, the high-rigidity portion 143 has a first rib 144 extending in the longitudinal direction of the upper insulating plate 140 and a second rib 145 extending in the lateral direction of the upper insulating plate 140 . However, the ribs of the high-rigidity portion may have other structures as long as they can improve the rigidity in the thickness direction at both ends of the upper insulating plate in the longitudinal direction.

(Other embodiments)
Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, without being limited to the above-described embodiment, it is possible to modify the above-described embodiment as appropriate without departing from the spirit thereof.

In Embodiment 1, the upper insulating plate 40 has the thick portions 43 that improve the rigidity in the thickness direction at both ends in the longitudinal direction. In Embodiment 2, the upper insulating plate 140 has the high-rigidity portion 143 including the first ribs 144 and the second ribs 145 that improve the rigidity in the thickness direction at both ends in the longitudinal direction. However, the upper insulating plate may have any other configuration as long as it can improve the rigidity in the thickness direction at both ends in the longitudinal direction.

In each of the above-described embodiments, the thick portion 43 is the length of the electrode body 30 in the bottom plate portion 41 of the upper insulating plate 40 when the upper insulating plate 40 is viewed from the axial direction of the electrode body 30 in the sealed battery 1 . It is formed in a range overlapping with the R portions 30a located at both ends in the axial direction. However, when the upper insulating plate is viewed from the axial direction of the electrode body, the thick portion at least partially overlaps the R portions of the bottom plate portion of the upper insulating plate located at both ends in the longitudinal direction of the electrode body. It may be formed as

In each of the above-described embodiments, the upper insulating plates 40 and 140 are plate-like members having rectangular short sides formed in an arc shape in plan view. However, the upper insulating plate may be a member of any shape as long as it can electrically insulate the electrode body and the cover plate. In order to electrically insulate the cover plate and the electrode body wound in an elliptical shape when viewed from the axial direction, the upper insulating plate is arranged in the short axis direction of the electrode body when viewed from the axial direction of the electrode body. It has a shape that is longer in the long axis direction than the length of

In each of the embodiments described above, the sealed battery 1 is configured as a lithium ion battery. However, the sealed battery may be a battery other than a lithium ion battery.

In each of the embodiments described above, the battery case 2 is formed in a flat shape with the width direction being greater than the thickness direction. However, the battery case may have any shape as long as it has a bottomed cylindrical outer can and a cover plate connected to the opening of the outer can while covering the opening of the outer can. may be

In the present invention, an electrode body in which a sheet-like positive electrode, a negative electrode, and a separator are laminated in the thickness direction and wound in an elliptical shape, and an insulating plate positioned in the axial direction of the electrode body are placed in a battery case. It can be used for housed sealed batteries.

1 sealed battery 2 battery case 10 outer can 11 bottom 12 side wall 20 cover plate 30 electrode body 31 positive electrode 32 negative electrode 33 separator 34 positive electrode lead 35 negative electrode lead 40, 140, X upper insulating plate (insulating plate)
40a through hole 41, Xa bottom plate portion 41a hole portion 42, Xb outer peripheral rib 43 thick portion (high rigidity portion)
50 bottom insulator 143 high rigidity portion 144 first rib 145 second rib P axis

Claims (3)

an electrode body in which a sheet-like positive electrode, a negative electrode and a separator are laminated in the thickness direction and wound in an elliptical shape about the axis;
An insulator positioned in the axial direction with respect to the electrode body so that its thickness direction coincides with the axial direction of the electrode body, and is longer in the long axis direction than the length in the short axis direction of the electrode body when viewed from the axial direction. a board;
a battery case in which the electrode body and the insulating plate are housed;
with
The insulating plate is
a flat plate;
an outer peripheral rib positioned on the outer peripheral edge of the flat plate portion and extending in the thickness direction;
has
At both ends in the longitudinal direction of the flat plate portion, rigidity higher than the other portions of the flat plate portion is provided at positions at least partially overlapping with ends in the longitudinal direction of the electrode body when viewed from the axial direction. A highly rigid portion having
The high-rigidity portion is
a first rib extending in the longitudinal direction;
Having a second rib that intersects with the first rib when viewed in the thickness direction,
sealed battery. The sealed battery of claim 1,
The high-rigidity portions are provided at both ends of the flat plate portion in the longitudinal direction in a range overlapping the ends of the electrode body in the longitudinal direction when viewed from the axial direction. The sealed battery according to claim 1 or 2 ,
The sealed battery, wherein the first rib and the second rib are provided on a surface of the flat plate portion opposite to the electrode assembly.

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