JP2020149916A - Insulation plate for sealed battery and sealed battery including the same - Google Patents

Abstract

To provide an insulation plate for sealed battery that can be applied to sealed batteries of different sizes, and a sealed battery including the same.SOLUTION: An upper insulation plate 40 is an insulation plate for sealed battery in which an opening 10a is housed in an exterior can 10 covered by a lid plate 20 such that an electrode body 30 and the lid plate 20 are electrically insulated. The upper insulation plate 40 includes a flat plate-shaped bottom plate 41 which is long in one direction, and a bent portion 43 located at at least one end of the bottom plate 41 in the one direction and capable of adjusting the length of the upper insulation plate 40 in the one direction by bending in the thickness direction of the bottom plate 41.SELECTED DRAWING: Figure 4

Description

The present invention relates to an insulating plate for a sealed battery that electrically insulates an electrode body and a lid plate that covers an opening of an outer can, and a sealed battery provided with the insulating plate.

There is known an insulating plate for a sealed battery that electrically insulates an electrode body housed in an outer can and a lid plate that covers an opening of the outer can. As a sealed battery provided with such an insulating plate for a sealed battery, for example, a configuration disclosed in Patent Document 1 is known. In the sealed battery disclosed in Patent Document 1, a battery element obtained by stacking a positive electrode and a negative electrode via a separator and winding them flat is housed in a square battery can. , The battery can is sealed with a lid. An upper insulating plate for preventing a short circuit is arranged between the battery element and the lid body.

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

JP-A-2007-188711

By the way, in the case of a sealed battery having the above-mentioned configuration, it is necessary to match the size of the upper insulating plate (hereinafter, insulating plate) with the size of the battery can (hereinafter, battery case) and the battery element (hereinafter, electrode body). There is. Therefore, it is necessary to prepare an insulating plate of an appropriate size according to the size of the battery case and the electrode body.

In this way, if an insulating plate of an appropriate size is prepared according to the size of the battery case and the electrode body, it is necessary to design the insulating plate according to the size of the battery case and the electrode body, and the manufacturing cost of the sealed battery Increases.

An object of the present invention is to provide an insulating plate for a sealed battery that can be applied to sealed batteries of different sizes, and a sealed battery provided with the insulating plate.

The insulating plate for a sealed battery according to an embodiment of the present invention is a sealed battery in which an electrode body and the lid plate are electrically insulated from each other in an outer can whose opening is covered with a lid plate. Insulation plate for use. This insulating plate for a sealed battery is located at at least one end of a flat plate-shaped insulating plate main body long in one direction and the insulating plate main body in the one direction, and is bent in the thickness direction of the insulating plate main body. It has a bent portion whose length in one direction of the insulating plate for a sealed battery can be adjusted (first configuration).

By bending the bent portion in the thickness direction of the insulating plate body, the length of the insulating plate for the sealed battery can be adjusted in one direction. Therefore, the insulating plate for the sealed battery can be used as a sealed battery of a different size. Can be applied. As a result, it is not necessary to design and manufacture the insulating plate for the sealed battery for each size of the sealed battery, so that the manufacturing cost of the sealed battery can be reduced.

Moreover, the bent portion can be displaced in the thickness direction by bending in the thickness direction of the sealed battery insulating plate. Therefore, even if the sealed battery receives a strong impact due to dropping or the like, it is possible to prevent the one-way end of the sealed battery insulating plate from being deformed by receiving a force from the electrode body in the sealed battery. it can.

In the first configuration, the bent portion is configured to bend to the side opposite to the side where the electrode body is located with respect to the insulating plate main body (second configuration).

As a result, it is possible to prevent the bent portion of the insulating plate for the sealed battery from interfering with the electrode body. Therefore, a more compact sealed battery can be obtained.

In the first or second configuration, the bent portion is provided on one surface in the thickness direction of the insulating plate body so as to extend in a direction intersecting the one direction, and is more than the thickness of the insulating plate body. Also has a thin thin wall (third configuration).

As a result, the bent portion can be easily bent in the thickness direction of the insulating plate main body. Therefore, the above-mentioned first configuration can be realized more easily.

In the third configuration, the thin-walled portion includes a groove portion provided on at least one surface of the thickness direction surface of the insulating plate body so as to extend in a direction intersecting the one direction (fourth configuration). Constitution). Thereby, the structure of the thin-walled portion of the bent portion can be easily realized.

In any one of the first to fourth configurations, the sealed battery insulating plate further has an outer peripheral rib located on the outer peripheral edge of the insulating plate main body and extending in the thickness direction. The bent portion is configured to bend toward the outer peripheral rib side with respect to the insulating plate main body. A storage portion for preventing interference with the bent portion is provided at the end of the outer peripheral rib in one direction in which the bent portion is located (fifth configuration).

This makes it possible to prevent the bent portion from interfering with the outer peripheral rib when the bent portion is bent. Therefore, a compact sealed battery can be obtained even when the bent portion is bent.

In any one of the first to fourth configurations, the sealed battery insulating plate further has an outer peripheral rib located on the outer peripheral edge of the insulating plate main body and extending in the thickness direction. The outer peripheral rib is provided with a slit extending in the thickness direction (sixth configuration).

As a result, even when the outer peripheral rib comes into contact with the inner surface of the battery case with the sealed battery insulating plate housed in the battery case, the outer peripheral rib is easily deformed by the slit. Therefore, even if the size of the battery case is different, the sealed battery insulating plate can be stored in the battery case.

In the sixth configuration, the outer peripheral rib is provided with a protruding portion protruding in a direction intersecting the one direction. The slit is provided on the outer peripheral rib so as to be aligned with the protruding portion in the one direction (seventh configuration).

As a result, when the protruding portion comes into contact with the inner surface of the battery case while the sealed battery insulating plate is housed in the battery case, the outer peripheral rib is easily deformed by the slit. Therefore, even if the size of the battery case is different, the sealed battery insulating plate can be stored in the battery case.

In the sealed battery according to the embodiment of the present invention, the sealed battery has an electrode body, an outer can for accommodating the electrode body, a lid plate covering the opening, and the outer can. The sealed battery insulating plate according to any one of claims 1 to 7, which is housed inside and electrically insulates the electrode body and the lid plate (eighth configuration).

The insulating plate for a sealed battery according to an embodiment of the present invention is located at at least one end of a flat plate-shaped insulating plate main body long in one direction and the insulating plate main body in the one direction, and is the insulating plate main body. It has a bent portion whose length in one direction can be adjusted by bending in the thickness direction of the sealed battery insulating plate. As a result, an insulating plate for a sealed battery that can be applied to sealed batteries of different sizes can be obtained.

FIG. 1 is a perspective view showing a schematic configuration of a sealed battery according to an embodiment 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 the electrode body. FIG. 4 is a perspective view showing a schematic configuration of the upper insulating plate. FIG. 5 is a sectional view taken along line VV in FIG. FIG. 6 is a perspective view schematically showing the positional relationship between the upper insulating plate and the electrode body. FIG. 7 is a plan view of the upper insulating plate. FIG. 8 is a perspective view showing a state in which the bent portion of the upper insulating plate is bent in the thickness direction and the upper insulating plate is arranged so that the thickness direction coincides with the electrode body in the axial direction. FIG. 9 is a diagram schematically showing the relationship between the upper insulating plate and the electrode body when the sealed battery provided with the upper insulating plate receives an impact.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals 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 a first embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. Note that, in FIGS. 1 and 2, the configuration of the sealed battery 1 is simplified and shown for the sake of explanation.

The sealed battery 1 includes a bottomed tubular outer can 10, a lid plate 20 that covers the opening 10a of the outer can 10, an electrode body 30, and an upper insulating plate 40 (insulating plate for a sealed battery). It is provided with a bottom insulator 50.

The electrode body 30, the upper insulating plate 40, and the bottom insulating body 50 are housed in the outer can 10. By welding the opening 10a and the outer peripheral portion of the lid plate 20 in a state where the opening 10a of the outer can 10 is covered with the lid plate 20, a columnar battery case 2 having a space inside is configured. The battery case 2 is formed in a flat shape in which the width direction (horizontal direction in FIG. 1) is larger than the thickness direction (paper surface direction in FIG. 1).

In the battery case 2, in addition to the electrode body 30, the upper insulating plate 40 and the bottom insulating body 50, a connecting plate 27 electrically connected to the electrode body 30 and a non-aqueous electrolytic solution (hereinafter, simply electrolytic solution) are contained. ) Etc. are also enclosed.

FIG. 3 is a perspective view showing a schematic configuration of the electrode body 30. The electrode body 30 has a positive electrode 31 and a negative electrode 32 formed in a sheet shape, for example, in a state of being superposed so that a separator 33 is positioned between the two, in a spiral shape as shown in FIGS. 2 and 3. It is a wound electrode body formed by winding. Specifically, the electrode body 30 is formed in a flat shape by being wound around the axis P in a state where the positive electrode 31, the negative electrode 32, and the separator 33 are superposed in the thickness direction and then crushed. 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 in an elliptical shape about the axis P.

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

Here, in FIG. 2, only a few layers on the outer peripheral side of the electrode body 30 are shown. However, in FIG. 2, only the illustration of the inner peripheral side portion of the electrode body 30 is omitted, and as a matter of course, the positive electrode 31, the negative electrode 32 and the separator 33 also exist on the inner peripheral side of the electrode body 30. ..

The positive electrode 31 has positive electrode active material layers containing a positive electrode active material provided on both sides of a positive electrode current collector made of a metal foil such as aluminum. Specifically, the positive electrode 31 is coated with a positive electrode mixture containing a positive electrode active material, a conductive auxiliary agent, a binder, etc., which are lithium-containing oxides capable of storing and releasing lithium ions, on a positive electrode current collector made of aluminum foil or the like. It is formed by drying. As the lithium-containing oxide as the positive electrode active material, for example, a lithium cobalt oxide such as LiCoO ₂ , a lithium manganese oxide such as LiMn ₂ O ₄ , or a lithium composite oxide such as a lithium nickel oxide such as LiNiO ₂ is used. Is preferable. As the positive electrode active material, only one kind of substance may be used, or two or more kinds of substances may be used. Further, the positive electrode active material is not limited to the above-mentioned substances.

The negative electrode 32 is formed by providing a negative electrode active material layer containing a negative electrode active material on both sides of a negative electrode current collector made of a metal foil such as copper. Specifically, the negative electrode 32 is formed by applying a negative electrode mixture containing a negative electrode active material capable of occluding / releasing lithium ions, a conductive auxiliary agent, a binder, etc. onto a negative electrode current collector made of copper foil or the like and drying the negative electrode 32. It is formed. As the negative electrode active material, for example, it is preferable to use a carbon material (graphites, thermally decomposed carbons, cokes, glassy carbons, etc.) capable of storing and releasing lithium ions. The negative electrode active material is not limited to the above-mentioned substances.

Further, the positive electrode lead 34 is connected to the positive electrode 31 of the electrode body 30, while the negative electrode lead 35 is connected to the negative electrode 32. As a result, the positive electrode lead 34 and the negative electrode lead 35 are pulled out to the outside of the electrode body 30. The tip end side of the positive electrode lead 34 is connected to the lid plate 20. On the other hand, the tip end side of the negative electrode lead 35 is connected to the negative electrode terminal 22 via a connecting plate 27, as will be described later.

The outer can 10 is a bottomed tubular member made of an aluminum alloy, and constitutes the battery case 2 together with the lid plate 20. As shown in FIG. 1, the outer can 10 is a bottomed tubular member having a bottom surface 11 having a rectangular short side formed in an arc shape. Specifically, the outer can 10 includes a bottom surface 11 and a flat tubular 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 corresponding to the long side direction of the bottom surface 11. Further, since the outer can 10 is joined to the lid plate 20 connected to the positive electrode lead 34 as described later, it also serves as the positive electrode terminal of the sealed battery 1.

As shown in FIG. 2, the bottom portion inside the outer can 10 is made of a polyethylene sheet for preventing a short circuit between the positive electrode 31 and the negative electrode 32 of the electrode body 30 via the outer can 10. The bottom insulator 50 is arranged. The electrode body 30 described above is arranged so that one end thereof is positioned on the bottom insulator 50.

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

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

The outer peripheral portion of the lid plate 20 is connected to the opening 10a of the outer can 10 by welding while covering the opening 10a of the outer can 10. Like the outer can 10, the lid plate 20 is made of an aluminum alloy member, and the short side of the rectangle is formed in an arc shape so that it can be fitted inside the opening 10a of the outer can 10.

A through hole 20a is formed in the central portion of the lid plate 20 in the longitudinal direction, and a cleavage vent 23 and an injection port 24 are formed in the longitudinal direction of the lid plate 20 with the through hole 20a interposed therebetween. That is, the lid plate 20 is provided with a cleavage vent 23, a through hole 20a, and an injection port 24 arranged side by side in the longitudinal direction of the lid 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 lid plate 20. Specifically, a substantially cylindrical insulating packing 21 through which a substantially columnar negative electrode terminal 22 is inserted is fitted to the peripheral edge of the through hole 20a.

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

The negative electrode terminal 22 is electrically connected to the connecting plate 27 by penetrating the connecting plate 27 made of nickel for the shaft portion. The connecting 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 lid plate 20, that is, from the negative electrode terminal 22 toward the cleavage vent 23. As a result, the negative electrode terminal 22 is electrically connected to the negative electrode 32 of the electrode body 30 via the connecting plate 27 and the negative electrode lead 35.

A rectangular terminal insulating plate 26 is arranged between the connecting plate 27 and the lid plate 20 in a plan view for electrically insulating the two. Like the connecting plate 27, the terminal insulating plate 26 is also penetrated by the shaft portion of the negative electrode terminal 22 and is arranged so as to extend toward the cleavage vent 23. That is, the shaft portion of the negative electrode terminal 22 penetrates the lid plate 20 and also penetrates the terminal insulating plate 26 and the connecting plate 27.

The injection port 24 formed in the lid plate 20 is a through hole for injecting the electrolytic solution into the battery case 2. The injection port 24 is formed in a substantially circular shape in a plan view. As shown in FIG. 2, the injection port 24 is sealed by a sealing plug 25 having a T-shaped cross section. After injecting the electrolytic solution into the battery case 2, the outer peripheral portion of the flange portion of the sealing plug 25 and the lid plate 20 are provided so that a gap is not formed between the sealing plug 25 and the peripheral portion of the injection port 24. Is joined by laser welding.

As shown in FIG. 1, the cleavage vent 23 is formed in an oval shape that is long in the longitudinal direction of the lid plate 20 when the lid plate 20 is viewed in plan view, that is, when the battery case 2 is viewed from above. As shown in FIG. 2, the cleavage vent 23 surrounds an elliptical thin-walled valve body 23a having a thickness smaller than the thickness of other parts of the lid plate 20 and an outer circumference of the thin-walled valve body 23a in a plan view. It has a thin-walled portion 23b provided with a groove on the upper surface side of the lid plate 20.

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

(Upper insulation plate)
Next, the configuration of the upper insulating plate 40 that electrically insulates the electrode body 30 and the lid plate 20 will be described in detail with reference to FIGS. 2, 4 to 8.

FIG. 4 is a perspective view showing a schematic configuration of the upper insulating plate 40. FIG. 5 is a sectional view taken along line VV in FIG. FIG. 6 is a perspective view showing a state in which the upper insulating plate 40 is arranged so that the thickness direction coincides with the electrode body 30 in the axial direction. FIG. 7 is a plan view schematically showing the relationship between the upper insulating plate 40 and the side wall 12 of the battery case 2. In FIG. 7, for the sake of explanation, the side wall 12 and the electrode body 30 of the battery case 2 are shown by alternate long and short dash lines.

FIG. 8 is a perspective view showing a state in which the bent portion 43 of the upper insulating plate 40 is bent in the thickness direction, and the upper insulating plate 40 is arranged so that the thickness direction coincides with the electrode body 30 in the axial direction. It is a figure.

As shown in FIGS. 4 and 6, the upper insulating plate 40 is a plate-shaped member formed in a rectangular shape in a plan view. The upper insulating plate 40 has a plate-shaped bottom plate portion 41 (insulating plate main body) and an outer peripheral rib 42 extending in the longitudinal direction and the thickness direction of the bottom plate portion 41 at the outer peripheral edge of the bottom plate portion 41. In FIGS. 4 and 5, reference numeral 44 is a reinforcing rib extending in the lateral direction of the upper insulating plate 40. In the present embodiment, the longitudinal direction of the upper insulating plate 40 corresponds to one direction.

As shown in FIGS. 4 and 6, the bottom plate portion 41 is formed in a rectangular shape in a plan view. As shown in FIGS. 2 and 6, 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 body 30. That is, the upper insulating plate 40 is located 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 major axis direction than the length in the minor axis direction of the electrode body 30 when viewed from the axial direction.

The bottom plate portion 41 is provided with a hole portion 41a. By providing the hole 41a in the bottom plate 41, when the electrolytic solution is injected into the battery case 2 from the injection port 24, the electrolytic solution passes through the hole 41a of the upper insulating plate 40 and enters the battery case 2. It is filled efficiently.

As shown in FIGS. 4 to 7, the bottom plate portion 41 has bent portions 43 that can be bent in the thickness direction at both ends in the longitudinal direction. The bent portion 43 is bent with respect to the bottom plate portion 41 on the side opposite to the electrode body 30, that is, on the side where the outer peripheral rib 42 described later is located. 4 and 5 show the bending direction of the bent portion 43 with solid arrows. The length of the upper insulating plate 40 in the longitudinal direction can be adjusted by bending the bent portion 43 in the thickness direction.

Specifically, the bent portion 43 has a bent portion main body 43a and a thin-walled portion 43b. The bent portion main body 43a is located outward in the longitudinal direction with respect to both ends in the longitudinal direction of the bottom plate portion 41, respectively. The bent portion main body 43a is partitioned from the bottom plate portion 41 by a thin-walled portion 43b. The bent portion main body 43a is provided with a rib 45 on an extension line of the outer peripheral rib 42 described later. A rib inclined portion 45a is provided on the thin-walled portion 43b side of the rib 45 so that the height of the rib 45 gradually decreases from the end portion in the longitudinal direction toward the thin-walled portion 43b.

As shown in FIG. 5, the thin-walled portion 43b includes groove portions 43c and 43d formed on both surfaces of the bottom plate portion 41, respectively. The groove portion 43c is provided on the surface of the bottom plate portion 41 on the side where the outer peripheral rib 42 is provided. The groove portion 43d is provided on the surface of the bottom plate portion 41 on the side where the electrode body 30 is located in the sealed battery 1. The groove portion 43c and the groove portion 43d are formed so as to extend at the same position in the longitudinal direction of the bottom plate portion 41 in the lateral direction of the bottom plate portion 41. As a result, the thin-walled portion 43b has a smaller wall thickness than the other portions of the bottom plate portion 41. The thin portion 43b may include only one of the groove portions 43c and 43d.

As shown in FIG. 8, the bent portion 43 having the above-described configuration can be bent in the thickness direction of the bottom plate portion 41 by the thin-walled portion 43b. Thereby, the upper insulating plate 40 can be applied to a closed type battery having a battery case and an electrode body of different sizes. In FIG. 8, reference numeral 130 is an electrode body having a length shorter in the semimajor direction than the electrode body 30.

As shown in FIGS. 6 and 7, the bent portions 43 are located at both ends of the electrode body 30 in the long axis direction 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 so as to overlap the R portion 30a.

In the present embodiment, the thickness of the bent portion main body 43a is constant in the longitudinal direction and the lateral direction. The thickness of the bent portion main body 43a may change in at least one direction of the upper insulating plate 40 in the longitudinal direction and the lateral direction.

As shown in FIGS. 4 to 8, a pair of outer peripheral ribs 42 are provided at both ends of the bottom plate portion 41 in the lateral direction when viewed from the thickness direction of the bottom plate portion 41 so as to extend in the longitudinal direction of the bottom plate portion 41. ing. The pair of outer peripheral ribs 42 are located between the thin portions 43b of the bent portions 43 located at both ends of the upper insulating plate 40 in the longitudinal direction of the upper insulating plate 40. The pair of outer peripheral ribs 42 project outward in the thickness direction from one surface of the bottom plate portion 41. The one surface is the surface opposite to the side where the electrode body 30 is located, that is, the upper insulating plate when the upper insulating plate 40 is arranged in the battery case 2 in the axial direction with respect to the electrode body 30. It is a surface located on the 20 side of the lid plate of 40.

The pair of outer peripheral ribs 42 described above can secure a distance required for electrical insulation between the electrode body 30 and the lid plate 20, and can protect the positive electrode lead 34 and the negative electrode lead 35 in the battery case 2. it can.

Each of the pair of outer peripheral ribs 42 is provided with outer peripheral rib inclined portions 42a at both ends in the longitudinal direction of the upper insulating plate 40 so that the height of the outer peripheral ribs 42 gradually decreases toward the thin portion 43b. By providing the outer peripheral rib inclined portion 42a on the pair of outer peripheral ribs 42, it is possible to prevent the rib 45 of the bent portion 43 from interfering with the outer peripheral rib 42 when the bent portion 43 is bent at the thin portion 43b. Therefore, the outer peripheral rib inclined portion 42a functions as a storage portion for preventing interference with the bent portion 43.

Moreover, as described above, since the rib 45 of the bent portion 43 is also provided with the rib inclined portion 45a, when the bent portion 43 is bent, the rib 45 of the bent portion 43 and the outer peripheral rib 42 Can be more reliably prevented from interfering with.

Each of the pair of outer peripheral ribs 42 is provided with a plurality of projecting portions 46 projecting outward in the lateral direction (direction intersecting one direction) of the upper insulating plate 40 at both ends in the longitudinal direction of the upper insulating plate 40. Has been done. The plurality of projecting portions 46 are semicircular when the upper insulating plate 40 is viewed in a plane.

In the present embodiment, a pair of projecting portions 46 are provided at both ends of the upper insulating plate 40 in the longitudinal direction. The pair of projecting portions 46 are provided at positions facing each other in the longitudinal direction of the upper insulating plate 40.

By providing the protruding portion 46 on the pair of outer peripheral ribs 42 in this way, as shown in FIG. 7, the protruding portion 46 is the side wall of the battery case 2 in a state where the upper insulating plate 40 is housed in the battery case 2. Engage with 12. As a result, the upper insulating plate 40 can be positioned in the battery case 2.

Each of the pair of outer peripheral ribs 42 is provided with a slit 47 along with the protruding portion 46. The slit 47 extends in the thickness direction of the upper insulating plate 40. The protruding portion 46 is located closer to the end portion in the longitudinal direction than the slit 47 in the longitudinal direction of the pair of outer peripheral ribs 42. As a result, when the protruding portion 46 of the upper insulating plate 40 comes into contact with the inner surface of the side wall 12 of the battery case 2, the pair of outer peripheral ribs 42 are easily deformed by the slit 47. Therefore, the outer peripheral rib 42 of the upper insulating plate 40 can be easily engaged with the inner surface of the battery case 2.

Further, even if the length of the upper insulating plate 40 in the lateral direction is slightly larger than the inner dimension of the battery case 2, the outer peripheral rib 42 is easily deformed by the slit 47, so that the upper insulating plate 40 is inside the battery case 2. Can be stored. Therefore, the upper insulating plate 40 can be housed in battery cases of different sizes.

With the above configuration, an upper insulating plate 40 applicable to sealed batteries of different sizes can be obtained.

By the way, when the sealed battery is impacted at the corners as shown by the shaded arrows in FIG. 9 due to dropping or the like, the upper insulating plate 40 has an electrode body as shown by the white arrows in FIG. The force is input from 30.

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 in the R portions 30a located at both ends in the long axis direction when viewed from the axial direction. Therefore, when the sealed battery is repeatedly subjected to a strong impact and the R portion 30a of the electrode body 30 repeatedly contacts the bottom plate portion of the upper insulating plate, the bottom plate portion may be deformed in the thickness direction.

On the other hand, in the present embodiment, the upper insulating plate 40 has bent portions 43 at both ends in the longitudinal direction. As described above, the bent portion 43 is the R portion 30a located at both ends of the electrode body 30 in the long axis direction 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 at an overlapping position. The bent portion 43 can be displaced in the thickness direction by being bent in the thickness direction of the upper insulating plate 40 by the thin portion 43b.

As a result, when the sealed battery 1 is impacted as described above, the bent portion 43 of the upper insulating plate 40 is displaced in the thickness direction by the force received from the electrode body 30 as shown by the solid line arrow in FIG. To do. As a result, it is possible to prevent the bottom plate portion 41 of the upper insulating plate 40 from being deformed by the force received from the electrode body 30.

From the above, the upper insulating plate 40 of the present embodiment is located at at least one end of the flat bottom plate portion 41 long in one direction and the bottom plate portion 41 in the one direction, and is bent in the thickness direction of the bottom plate portion 41. Thereby, the upper insulating plate 40 has a bent portion 43 whose length in one direction can be adjusted.

Since the length of the upper insulating plate 40 in one direction can be adjusted by bending the bent portion 43 in the thickness direction of the bottom plate portion 41, the upper insulating plate 40 can be applied to sealed batteries of different sizes. it can. As a result, it is not necessary to design and manufacture the upper insulating plate for each size of the sealed battery, so that the manufacturing cost of the sealed battery can be reduced.

Moreover, the bent portion 43 can be displaced in the thickness direction by bending in the thickness direction of the upper insulating plate 40. Therefore, even when the sealed battery 1 receives a strong impact due to dropping or the like, it is possible to prevent the end portion of the upper insulating plate 40 in one direction from being deformed by receiving a force from the electrode body 30 in the sealed battery 1. ..

(Other embodiments)
Although the embodiment of the present invention has been described above, the above-described embodiment is merely an example for carrying out the present invention. Therefore, the embodiment is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented within a range that does not deviate from the gist thereof.

In the above embodiment, the thin-walled portion 43b of the upper insulating plate 40 includes groove portions 43c and 43d provided on both sides of the bottom plate portion 41, respectively. However, the thin-walled portion may have only a groove portion provided on one surface of the bottom plate portion. Further, the thin-walled portion may have a structure other than the groove as long as the wall thickness is thinner than the other portion of the bottom plate portion.

In the above embodiment, the bent portion 43 of the upper insulating plate 40 has a thin portion 43b. However, the bent portion may have another configuration such as a notch as long as it can be bent in the thickness direction with respect to the bottom plate portion.

In the above embodiment, the upper insulating plate 40 is a rectangular plate-shaped member in a plan view. However, the upper insulating plate is a member having any shape, such as a plate-shaped member in which the short side of the rectangle is formed in an arc shape, as long as the electrode body and the lid plate can be electrically insulated. You may. In order to electrically insulate the lid plate from the electrode body wound in an elliptical shape when viewed from the axial direction, the upper insulating plate is provided in the minor 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 semi-major axis than the length of.

In the above embodiment, the electrode body 30 is a wound electrode body formed by spirally winding the positive electrode 31, the negative electrode 32, and the separator 33, which are formed in a sheet shape, in a state of being superposed in the thickness direction. Is. However, the electrode body may be an electrode body formed by laminating a sheet-shaped positive electrode, a negative electrode, and a separator in the thickness direction. Further, the electrode body may have another structure.

In the above embodiment, the sealed battery 1 is configured as a lithium ion battery. However, the sealed battery may be a battery other than the lithium ion battery.

In the above embodiment, the battery case 2 is formed in a flat shape in which the width direction is larger than the thickness direction. However, the battery case has any shape as long as it includes a bottomed tubular outer can and a lid plate connected to the opening of the outer can while covering the opening of the outer can. It may be.

The present invention can be used as an insulating plate for a closed battery in which the electrode body and the lid plate are housed so as to electrically insulate the electrode body and the lid plate in an outer can whose opening is covered with a lid plate.

1 Sealed battery 2 Battery case 10 Exterior can 10a Opening 11 Bottom surface 12 Side wall 20 Lid plate 30, 130 Electrode body 31 Positive electrode 32 Negative electrode 33 Separator 34 Positive electrode lead 35 Negative electrode lead 40 Upper insulating plate (insulating plate for sealed battery)
41 Bottom plate 41a Hole 42 Outer rib 42a Outer rib inclined part (storage part)
43 Folded part 43a Bent part main body 43b Thin wall part 43c Groove part 43d Groove part 44 Reinforcing rib 45 Rib 45a Rib inclined part 46 Protruding part 47 Slit 50 Bottom insulator P Axis line

Claims (8)

An insulating plate for a sealed battery in which the electrode body and the lid plate are housed so as to electrically insulate the electrode body and the lid plate in an outer can whose opening is covered with a lid plate.
A flat plate-shaped insulating plate body that is long in one direction,
A bent portion located at at least one end of the insulating plate main body in the one direction and capable of adjusting the length of the insulating plate for a closed battery in the one direction by bending in the thickness direction of the insulating plate main body. When,
Insulation plate for sealed batteries. In the insulating plate for a sealed battery according to claim 1,
The bent portion is an insulating plate for a sealed battery, which is configured to bend with respect to the insulating plate main body on the side opposite to the side where the electrode body is located. In the insulating plate for a sealed battery according to claim 1 or 2.
The bent portion is provided on one surface of the insulating plate main body in the thickness direction so as to extend in a direction intersecting with the one direction, and has a thin portion thinner than the thickness of the insulating plate main body. Insulation plate for. In the insulating plate for a sealed battery according to claim 3,
The thin-walled portion is an insulating plate for a sealed battery, which includes a groove portion provided on at least one surface of the insulating plate main body in the thickness direction so as to extend in a direction intersecting the one direction. The insulating plate for a sealed battery according to any one of claims 1 to 4.
Further having an outer peripheral rib located on the outer peripheral edge of the insulating plate body and extending in the thickness direction.
The bent portion is configured to be bent toward the outer peripheral rib side with respect to the insulating plate main body.
An insulating plate for a sealed battery, which is provided with a storage portion for preventing interference with the bent portion at the end of the outer peripheral rib in one direction in which the bent portion is located. .. The insulating plate for a sealed battery according to any one of claims 1 to 4.
Further having an outer peripheral rib located on the outer peripheral edge of the insulating plate body and extending in the thickness direction.
An insulating plate for a sealed battery, wherein the outer peripheral rib is provided with a slit extending in the thickness direction. In the insulating plate for a sealed battery according to claim 6,
The outer peripheral rib is provided with a protruding portion that protrudes in a direction intersecting the one direction.
The slit is an insulating plate for a sealed battery, which is provided on the outer peripheral rib so as to be aligned with the protruding portion in one direction. With the electrode body
An outer can having an opening and accommodating the electrode body,
A lid plate covering the opening and
The insulating plate for a sealed battery according to any one of claims 1 to 7, which is housed in the outer can and electrically insulates the electrode body and the lid plate.
A sealed battery.

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