JP2002093456A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively stop an electrolyte remaining on an insulating separator from oozing out to the upper surface of a sealing member. SOLUTION: This battery is provided with an electrode body 1 having a separator 1C installed between a positive plate 1A and a negative plate 1B, an armoring can 2 housing the electrode body 1, the sealing member 3 airtightly closing the opening part of the armoring can 2 through a gasket 4, and the insulating separator 5 located inside the armoring can 2 and installed between the electrode body 1 and the sealing member 3 to insulate the electrode body 1. The upper surface of the insulating separator 5 installed between the sealing member 3 and the electrode body 1 is formed into an uneven surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery which is hermetically sealed with a sealing body which fixes an opening of an outer can by caulking.

[0002]

2. Description of the Related Art A battery is manufactured in such a manner that an electrode body and an electrolyte are filled in a cylindrical outer can closing a bottom, and a sealing body is fixed in an opening to hermetically seal the battery. The structure to seal the outer can with the sealing body is caulking processing, a nylon gasket is sandwiched between the sealing body and the outer can to hermetically seal, and the boundary between the sealing body and the outer can is laser welded And hermetically sealed. The present invention relates to a battery for fixing a sealing body to an outer can by caulking. A conventional battery having this structure is manufactured in the process shown in FIG. 1 as follows.

(1) The positive electrode plate 1A and the negative electrode plate 1B are laminated via a separator 1C, and the wound electrode body 1 is inserted into an outer can 2 having a closed bottom. After the electrode body 1 is put, the insulating separator 5 is put on the upper surface of the electrode body 1. The insulating separator 5 is disposed on the upper surface of the outer peripheral portion of the electrode body 1 in order to prevent the peripheral wall 6 of the outer can 2 from coming into contact with the electrode body 1 and causing an internal short circuit. (2) The outer can 2 is grooved from the outer peripheral surface to provide the peripheral wall 6. The peripheral wall 6 is provided at a boundary between the electrode body 1 and the sealing body 3 and serves as a stopper for preventing the sealing body 3 from being pushed into the outer can 2. (3) The electrolytic solution is injected into the outer can 2 and permeates the electrode body 1. (4) The lead 12 connected to the electrode body 1 is connected to the sealing body 3 by spot welding. (5) After setting the sealing body 3 in the opening of the outer can 2, the opening edge of the outer can 2 is bent inward into an L-shape, and the L-shaped bent portion 1 is formed.
The sealing body 3 is sandwiched between the peripheral wall 3 and the peripheral wall 6 and fixed. In this state, the sealing body 3 is sandwiched via the gasket 4. The gasket 4 fixes the sealing body 3 in an airtight manner and insulates the sealing body 3 from the outer can 2. Therefore, the gasket 4 is made of an insulating material that is a rubber-like elastic body. (6) Finally, as shown by the arrow, the L-shaped bent portion 13 is pressed from above, and the gasket 4 is securely sandwiched between the L-shaped bent portion 13 and the peripheral wall 6 to be in an airtight state. . In this process,
The peripheral wall 6 is pressed from above and contacts the insulating separator 5. In this state, since the insulating separator 5 is provided between the peripheral wall 6 and the electrode body 1, the electrode body 1 does not contact the peripheral wall 6 and short-circuit.

[0004]

In the battery manufactured by the above steps, the electrolyte 14 adheres to the insulating separator 5 as shown in FIG. In this state, as shown in FIG.
When the L-shaped bent portion 13 is pressed from above, the electrolyte solution 14 remaining on the insulating separator 5 is removed.
Between the gasket 4 and the outer can 2, and seeps onto the upper surface of the sealing body 3.
Adhered to the surface of the sealing body 3 and caused corrosion. The electrolytic solution attached to the upper surface of the sealing body is removed by washing with water after being manufactured, but is not completely removed, or
What remained between the gasket 4 and the outer can 2 oozed out over time, causing the sealing body to corrode over time.

The present invention has been developed to solve this drawback. An important object of the present invention is to provide a battery that can effectively prevent the electrolyte remaining on the insulating separator from seeping out to the upper surface of the sealing body.

[0006]

The battery according to the present invention comprises an electrode body 1 having a separator 1C disposed between a positive electrode plate 1A and a negative electrode plate 1B, and an outer can housing the electrode body 1 therein. 2
And a sealing member 3 that hermetically closes the opening of the outer can 2 via a gasket 4, and an electrode disposed between the electrode body 1 and the sealing member 3 inside the outer can 2. An insulating separator that insulates the body. The insulating separator 5 provided between the sealing body 3 and the electrode body 1 has an uneven upper surface.

[0007] The insulating separator 5 is preferably a rough surface having a surface roughness of 0.35 or more, with an upper surface having an uneven surface. The insulating separator 5 may be provided with a radial groove 17 on the upper surface to form an uneven surface. Furthermore, the insulating separator 5 can be formed as a plastic molded body with an upper surface having an uneven surface. Further, the insulating separator 5 may be coated on its upper surface with a hydrophilic film.

Further, the battery of the present invention may be provided with a peripheral wall 6 protruding from the inner surface of the outer can 2. This peripheral wall 6
Is provided along the upper edge of the electrode body 1 to prevent the sealing body 3 from being pushed deep into the outer can 2. This battery is
An insulating separator 5 is provided between the electrode body 1 and the peripheral wall 6.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. However, the following examples illustrate a battery for embodying the technical idea of the present invention, and the present invention does not limit the battery to the following.

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”.
However, the members described in the claims are not limited to the members of the embodiments.

The battery shown in FIG. 4 has a positive electrode plate 1A and a negative electrode plate 1A.
B, an electrode body 1 having a separator 1C disposed therebetween,
An outer can 2 containing the electrode body 1 and an outer can 2
And an insulating separator disposed above the electrode body 1 to prevent the electrode body 1 from contacting the outer can 2 and short-circuiting. 5 is provided. In the battery, the sealing body 3 is fixed by caulking the opening of the outer can 2. The battery shown in this figure is a secondary battery such as a nickel-hydrogen battery, a nickel-cadmium battery, and a lithium ion secondary battery.

In the case where the battery is a nickel-hydrogen battery, an electrode plate having a core coated with an active material mainly composed of a hydrogen storage alloy is used as a negative electrode plate, and a slurry is formed on a nickel core body as a positive electrode plate. An electrode plate which is impregnated with an active material mainly composed of nickel hydroxide and rolled is used. The positive electrode plate and the negative electrode plate are laminated and wound via a separator made of a nonwoven fabric made of polypropylene to form an electrode body. As the electrolyte, a potassium hydroxide-based electrolyte is used.

When the battery is a nickel-cadmium battery,
For the negative electrode plate, a band-shaped non-sintered negative electrode plate in which a paste active material containing cadmium oxide as a main component is filled in a core of the electrode plate is used. An electrode plate rolled by impregnation with an active material mainly composed of nickel oxide is used. However, the electrode plate can also be manufactured by a sintering method. This electrode plate is a nickel porous sintered substrate obtained by sintering a perforated thin steel sheet coated with a slurry containing an organic thickener in a reducing atmosphere and filling it with cadmium by chemical or electrolytic impregnation. A plate or a positive electrode plate filled with nickel. The positive electrode plate and the negative electrode plate are laminated and wound via a separator made of a nonwoven fabric made of polypropylene to form an electrode body. As the electrolyte, an electrolyte containing potassium hydroxide as a main component is used.

When the battery is a lithium ion secondary battery, a positive electrode plate is provided with a positive electrode active material which is a lithium-containing composite oxide,
For example, a positive electrode slurry containing LiCoO ₂ as a main component is rolled by applying a positive electrode slurry to a core, and a negative electrode plate is provided with a negative electrode active material which is a carbonaceous material that occludes and releases lithium ions. An electrode plate is used in which a negative electrode slurry containing graphite powder as a main component is applied to a core and rolled. The positive electrode plate and the negative electrode plate are laminated and wound via a separator, which is a microporous polyethylene film, to form an electrode body. As the electrolytic solution, a solution in which a lithium salt is dissolved as an electrolyte in a non-aqueous aprotic organic solvent is used.

In the battery shown in the figure, a positive electrode plate 1A and a negative electrode plate 1B laminated on each other via a separator 1C are wound. The spiral electrode body 1 is inserted into a cylindrical outer can 2. The spiral electrode body may be pressed from both sides to be deformed into an elliptical shape, and inserted into an elliptical or square outer can. Further, the electrode body to be inserted into the rectangular cylindrical outer can is manufactured by alternately laminating a plurality of positive and negative plates cut into a plate shape with polar plates having different polarities via a separator. Can also.

The outer can 2 is formed by processing a metal plate into a cylindrical shape with its bottom closed, and prevents the sealing body 3 from being pushed into the outer can 2 as shown in the sectional view of FIG. A peripheral wall 6 for fixing the sealing body 3 at a fixed position is provided so as to protrude from the inner surface. As the metal plate of the outer can 2, one obtained by plating an iron surface with nickel or the like, aluminum, an aluminum alloy, a clad material in which a plurality of metals are laminated, or the like is used. The outer can 2 having a closed bottom is manufactured by pressing a metal plate.

As shown by an arrow A in FIG. 5, the peripheral wall 6 is bent so as to linearly press the outer can 2 from the outside, and is bent so as to form a groove 9 on the outer side of the outer can 2. Provided. Since the peripheral wall 6 is a stopper for preventing the sealing body 3 from being pushed into the outer can 2, the peripheral wall 6 is provided between the sealing body 3 and the electrode body 1 and along the lower surface of the sealing body 3. After putting the electrode body 1 in the outer can 2, more precisely, putting the electrode body 1 in the outer can 2 so that the peripheral wall 6 is not in the way when the electrode body 1 is put in the outer can 2, It is provided after the insulating separator 5 is put thereon.

The gasket 4 is sandwiched between the outer can 2 and the sealing body 3 to insulate and connect the outer can 2 and the sealing body 3 in an airtight manner. The gasket 4 is generally manufactured by molding nylon. The gasket 4 is formed to have a U-shaped cross-sectional shape, and a fitting groove 4A for fitting the outer peripheral edge of the sealing body 3 is provided on the inner circumferential surface, and the sealing body 3 is fitted therein. . Further, since the gasket 4 is disposed on the inner surface of the outer can 2, the outer shape is formed to be equal to or slightly smaller than the inner shape of the outer can 2.

Since the outer can 2 is cylindrical, elliptical or square, the outer shape of the gasket 4 is formed in a circular, elliptical or square shape. Since the gasket 4 is provided along the outer peripheral edge of the sealing body 3, the entire shape is changed to the shape of the sealing body 3.
In a ring shape along the outer periphery of the ring.

The gasket 4 shown in FIG.
In order to more reliably prevent the contact with the lead and the lead, a cylindrical ring 8 along the inner surface of the peripheral wall 6 is integrally formed and provided. The illustrated gasket 4 has a cylindrical ring 8 extending vertically downward along the inner peripheral edge. The lower end of the cylindrical ring 8 is brought into contact with the insulating separator 5 in the step of caulking. In the battery incorporating the gasket 4, the upper side and the inner side of the peripheral wall 6 are covered with the gasket 4 and the lower side of the peripheral wall 6 is covered with the insulating separator 5. Thus, there is a feature that the upper and lower surfaces and the inner front surface of the peripheral wall 6 are covered, so that an internal short circuit can be reliably prevented. In the illustrated battery, the gasket 4 is integrally formed with the cylindrical ring 8, but as shown in FIG.
May be provided integrally with the insulating separator 5.

The sealing body 3 is manufactured by pressing a metal plate. The outer shape of the sealing body 3 is slightly smaller than the inner shape of the outer can 2 and is shaped to be fixed to the outer can 2 via a gasket 4. The sealing body 3 in FIG. 4 is fixed by spot welding two metal plates, and has a safety valve 10 built in between the two metal plates. The safety valve 10 is opened when the internal pressure of the outer can 2 becomes higher than the set pressure, thereby preventing the inner can of the outer can 2 from becoming abnormally high and destroying the outer can 2.
The sealing body 3 shown in the figure has a rubber-like elastic body 11 between two metal plates.
Into the safety valve 10. However, although not shown, the safety valve has a structure in which a rubber plate, a plate material, and a spring are disposed between two metal plates forming a sealing body, and the rubber plate is elastically pressed against the valve port by the spring. You can also.

The insulating separator 5 is disposed above the electrode body 1 in order to prevent the upper surface of the electrode body 1 and the leads 12 from coming into contact with the outer can 2 and causing an internal short circuit. In the battery shown in the figure, one electrode plate of the electrode body 1, for example, a negative electrode plate 1B is connected to an outer can 2, and the other electrode plate, a positive electrode plate 1A, is connected to a sealing body 3 via a lead 12. . Since the outer can 2 is on the negative side, the positive electrode plate 1A on the positive side of the electrode body 1 is provided with:
It is necessary to insulate the + side from the lead 12 connected to the sealing body 3. In particular, the outer can 2 shown in the drawing has the peripheral wall 6 protruding inward, so that the outer can 2 easily contacts the positive lead 12 and the positive electrode plate 1A to be short-circuited and needs to be insulated. The insulation separator 5 realizes this insulation. Since the insulating separator 5 insulates the upper surface of the electrode body 1 from the outer can 2, the outer shape is, for example, a shape that follows the inner shape of the outer can 2. It is formed into a ring shape that covers the outer periphery of the body 1. However, it goes without saying that the periphery of the electrode body 1 can be more reliably insulated by increasing the size of the insulating separator 5.

The insulating separator 5 is manufactured by molding an insulating material such as plastic into a ring shape. The upper surface of the insulating separator 5 has an uneven surface in order to remove the electrolytic solution 14 remaining thereon. The uneven surface is a rough surface provided with countless fine irregularities on the surface, or is realized by providing a large number of grooves. FIGS. 8 and 9 show a state where the electrolytic solution 14 adheres to the surface of the insulating separator 5 which is a smooth surface and a rough surface. The electrolytic solution 14 attached to the upper surface of the smooth insulating separator 5 is
As shown in FIG. 8, the surface tension becomes almost spherical.
On the other hand, the electrolytic solution adhering to the rough surface flows along the surface as shown in FIG. The state in which the electrolytic solution 14 adheres changes with the surface roughness which specifies the degree of the rough surface by a numerical value. The surface roughness is 0 when the mirror surface is a perfectly smooth surface, and the numerical value increases as the surface becomes rougher with more irregularities. Therefore, as the surface roughness increases,
This means that the upper surface of the insulating separator 5 becomes rough. FIG. 9 shows a state in which the electrolytic solution 14 adheres to the upper surface of the insulating separator 5 having a surface roughness of 1.

The state of the insulating separator 5 to which the electrolytic solution adheres changes depending on the surface roughness of the upper surface. When the surface roughness of the uneven surface is increased, the electrolyte flows smoothly as shown in FIG. 9, and the remaining electrolyte can be removed smoothly.
FIG. 10 shows an insulating separator 5 having different surface roughness of the uneven surface.
7 is a graph showing the percentage of electrolyte oozing out of a battery assembled in the same manner except for using. This figure shows a characteristic that, based on a battery (100%) using an insulating separator having an uneven surface having a surface roughness of 0.2 as a reference, the oozing out of the electrolyte decreases as the surface roughness increases. ing.

As shown in this figure, as the surface roughness of the uneven surface on the upper surface of the insulating separator 5 is increased, the amount of the electrolyte oozed out after caulking can be significantly reduced. In the battery using the insulating separator 5 having the upper surface roughness of 0.35 or more, the seepage of the electrolyte can be reduced to 以下 or less. When the surface roughness is set to 0.7 or more, the exudation of the electrolyte is reduced to 1/5 or less, and when the surface roughness is set to 1 or more, the exudation of the electrolyte is reduced to 1/3 or less.
It is reduced to 10 or less. Therefore, the battery of the present invention
The surface roughness of the upper surface of the insulating separator 5 which is an uneven surface is preferably 0.35 or more, more preferably 0.5 or more,
It is optimally 0.7 or more, and ideally 1 or more.

As shown in FIG. 11, the insulating separator 5 may be provided with a radial groove 17 on the upper surface to form an uneven surface. The insulating separator 5 allows the electrolyte remaining on the upper surface to flow down along the groove 17 to prevent seepage during caulking.

Further, the insulating separator 5 may be provided with an electrolytic solution flowing down portion 7 for flowing down the remaining electrolytic solution 14 in addition to making the upper surface uneven. The insulating separator 5 shown in FIGS. 5 and 6 is provided with a gap 5A on the outer peripheral edge to form an electrolyte flow lower portion 7. The gap 5A, which is the lower part of the electrolyte solution 7, is provided inside the outer can 2 to allow the electrolyte solution to flow down. The insulating separator 5 has a polygonal outer shape and can be provided with a well-balanced gap portion 5A on the outer periphery. This insulating separator 5 can be provided with a well-balanced gap portion 5A on the outer periphery as an outer shape in which a corner portion of each side abuts on the inner surface of the outer can 2. The insulating separator 5 of FIG. 12 has an octagonal outer shape, and eight gaps 5A defined on the outer periphery can be provided as the electrolyte flow lower part 7.

The insulating separator 5 shown in FIG. 13 is provided with a plurality of convex portions 5B on the outer periphery, and a gap 5A which is the lower part 7 of the electrolytic solution flows between the convex portions 5B. This insulating separator 5
The outer shape is such that the tip of the convex portion 5B is in contact with the inner surface of the outer can. The protruding portion 5B has its tip abutted on the inner surface of the outer can 2 so that the insulating separator 5 can be set concentrically with the outer can.
At least three are provided. The illustrated insulating separator 5 is provided with eight convex portions 5B at equal intervals on the outer periphery.

Further, in the insulating separator 5 shown in the plan view of FIG. When the insulating separator 5 is set on the inner surface of the outer can, an infinite number of gaps are formed on the inner surface of the outer can due to unevenness, and the electrolyte remaining above the gap flows down. The insulating separator 5 having this shape is set concentrically with the outer can, as a shape in which the convex portion 5B of the outer peripheral edge having irregularities comes into contact with the inner surface of the outer can.

Further, the insulating separator 5 shown in the cross-sectional view of FIG. 15 and the plan view of FIG. And The outer shape of the insulating separator 5 is substantially equal to the inner shape of the outer can, or slightly smaller than the inner shape of the outer can, so that the insulating separator 5 can be set concentrically with the outer can. As shown in FIG. 17, the inclined surface 5a, which is the lower part of the electrolyte solution 7, allows the remaining electrolyte solution 14 to flow down to prevent seepage from the sealing body during caulking. The insulating separator 5 sloping downward is sandwiched between the electrode body 1 and the peripheral wall 6 by caulking to be deformed to a horizontal or almost horizontal state.

Although not shown, the insulating separator is provided with a gap at the outer peripheral edge, and a lower portion of the electrolyte flow is provided between the gap and the inclined surface as an inclined surface whose upper surface is inclined downward toward the outer periphery. You can also. In the insulating separator, the electrolytic solution flows in the outer peripheral direction along the inclined surface on the upper surface, and the electrolytic solution flows down and is removed from the gap provided on the outer periphery. Since the upper surface of the insulating separator having this structure is inclined upward toward the center, the opening edge on the center side approaches the inner periphery of the peripheral wall, so that the electrolyte may enter between the peripheral wall and the insulating separator. There is also a feature that can be effectively prevented.

Furthermore, the upper surface of the insulating separator can be coated with a hydrophilic film to allow the remaining electrolyte to flow down more smoothly. This film can be provided, for example, by applying a surfactant or by providing a titanium oxide film.

In the battery of the above embodiment, the peripheral wall 6 protruding inside the outer can 2 is provided between the sealing body 3 and the electrode body 1, and the insulating wall is provided between the peripheral wall 6 and the electrode body 1. Separator 5
Is arranged. However, the battery of the present invention has a structure in which a peripheral wall is not provided between the sealing body and the electrode body, the sealing body is fixed to the opening of the outer can, and further, an insulating separator is provided between the sealing body and the electrode body. Can be arranged. FIG. 18 and FIG.
In the battery shown in FIG. 9, a stopper ridge 15 is provided to protrude from the inner surface of the opening of the outer can 2, and the gasket 4 is sandwiched between the stopper ridge 15 and the outer peripheral edge of the sealing body 3. The second opening is hermetically closed. These batteries have the same structure as the batteries of the above-described embodiment except that the sealing body 3 is fixed to the outer can 2 via the gasket 4 with the stopper ridge 15 without providing the outer can 2 with a peripheral wall. Can be. Therefore, the above-mentioned thing can be used also for the insulating separator 5 arrange | positioned between the sealing body 3 and the electrode body 1.

The stopper ridge 15 is provided so as to protrude from the inner surface of the opening of the outer can 2. The stopper ridge 15 is shown in FIG.
As shown in FIG. 0, a part of the outer can 2 can be provided thick. Alternatively, as shown in FIG. 21, the outer can 2 may be pressed linearly from the outside and bent so as to form a groove on the outer surface to provide a stopper ridge 15 projecting from the inner surface. The stopper ridge 15 has a cross section of a mountain shape as shown in FIGS. 20 and 21 and a shape with a sharpened front edge, or a flat front edge as shown in FIG. The chevron-shaped stopper ridge 15 can bite into the gasket 4 to securely fix the sealing body 3. In addition, the stopper ridge 15 having a flat distal end has a feature that the stopper ridge 15 comes into close contact with the gasket with a predetermined width and can be securely sealed.

The stopper ridge 1 shown in FIGS.
The step 5 is provided in a step of manufacturing the outer can 2, that is, in a step before the electrode body 1 is inserted. However, the stopper ridge 15 shown in FIG. 21 can also be provided by putting the electrode body 1 in the outer can 2 and then pressing the outer can 2 linearly from the outside. Further, the exterior can 2 of FIG. 23 shows another example in which the stopper ridge 15 is provided after the electrode body 1 is inserted. The outer can 2 is provided with an outer peripheral ridge 16 so as to protrude to the outside of the outer can 2 in a process manufactured by processing a metal plate. When the outer side of the outer can 2 is pressed after the electrode body 1 is put in the outer can 2, the outer ridge 16 is pushed, and the stopper ridge 15 protrudes from the inner surface as shown by a chain line in the figure. As described above, in the structure in which the stopper ridge 15 is provided after the electrode body 1 is placed in the outer can 2, the stopper ridge 15 does not protrude from the inner surface of the outer can 2 when the electrode body 1 is placed. Can be put in smoothly.

Further, as shown in FIG. 24, the outer can 2
The stopper ridge 15 can be provided by bending the opening edge inward. The battery of the outer can 2 having this structure has a feature that the stopper ridge 15 can be cut into the outer peripheral surface of the gasket 4 and the sealing body 3 can be more securely fixed to the outer can 2 with the stopper ridge 15.

The stopper ridge 15 provided on the outer can 2
Cuts into the outer peripheral surface of the gasket 4 which is elastically deformed,
The sealing body 3 is firmly fixed to a fixed position of the outer can 2. When the stopper ridge 15 bites into the gasket 4, the outer peripheral surface of the gasket 4 is crushed linearly by the stopper ridge 15 so that the sealing body 3 does not come off from the outer can 2, and It is fixed so that it is not pushed. That is,
The sealing body 3 is fixed to the outer can 2 with sufficient strength in both directions indicated by arrows A and B in FIG.

In the battery having the above-described structure, the electrolyte remaining on the upper surface of the insulating separator 5 can be quickly removed by flowing down from the lower part 7 of the electrolyte.

[0039]

The battery of the present invention has the feature that the electrolyte remaining on the insulating separator can be effectively prevented from seeping out to the upper surface of the sealing body. This is because the battery of the present invention is disposed between the electrode body and the sealing body, and has an uneven upper surface of the insulating separator that insulates the electrode body. The state of the electrolytic solution attached to the upper surface of the insulating separator changes depending on the surface roughness. The insulating separator having an uneven upper surface makes it easier for the electrolytic solution to flow along the rough surface, so that the remaining electrolytic solution can be removed smoothly. Therefore, when the sealing body is fixed by caulking, the leakage of the electrolyte is significantly reduced, and the corrosion of the surface of the sealing body due to the leaking electrolyte can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a conventional battery manufacturing process.

FIG. 2 is a cross-sectional view showing a state in which an electrolytic solution is attached on an insulating separator in a conventional battery manufacturing process.

FIG. 3 is a cross-sectional view showing a state in which an electrolyte remaining on the insulating separator of the battery shown in FIG. 2 leaks out to the upper surface of the sealing body;

FIG. 4 is a sectional view of a battery according to an embodiment of the present invention.

5 is an exploded cross-sectional view showing a manufacturing process of the battery shown in FIG.

FIG. 6 is an enlarged sectional view of a main part of the battery shown in FIG.

FIG. 7 is a sectional view of a battery according to another embodiment of the present invention.

FIG. 8 is an enlarged sectional view showing a state in which an electrolytic solution adheres to an upper surface of an insulating separator having a smooth surface.

FIG. 9 is an enlarged cross-sectional view showing a state where an electrolytic solution adheres to an upper surface of an insulating separator having a rough surface.

FIG. 10 is a graph showing the relationship between the surface roughness of the uneven surface of the insulating separator and the percentage of the electrolyte leaking out.

FIG. 11 is a plan view showing an example of an insulating separator.

FIG. 12 is a horizontal sectional view showing a positional relationship between an outer can of the battery shown in FIG. 4 and an insulating separator.

FIG. 13 is a plan view showing another example of the insulating separator.

FIG. 14 is a plan view showing another example of the insulating separator.

FIG. 15 is a sectional view showing another example of the insulating separator.

16 is a plan view of the insulating separator shown in FIG.

FIG. 17 is a sectional view of a battery including the insulating separator shown in FIG.

FIG. 18 is a cross-sectional view of the upper part of a battery according to another embodiment of the present invention.

FIG. 19 is a sectional view of the upper part of a battery according to another embodiment of the present invention.

FIG. 20 is a partial cross-sectional front view showing an example of an outer can.

FIG. 21 is a partial cross-sectional front view showing another example of the outer can.

FIG. 22 is a partial sectional front view showing another example of the outer can.

FIG. 23 is a partial cross-sectional front view showing another example of the outer can.

FIG. 24 is a cross-sectional view of the upper part of a battery according to another embodiment of the present invention.

[Explanation of symbols]

1: Electrode body 1A: Positive electrode plate 1
B ... Negative electrode plate 1C ... Separator 2 ... Outer can 3 ... Sealing body 4 ... Gasket 4A ... Fitting groove 5 ... Insulating separator 5A ... Gap
5B ... convex part 5a ... inclined surface 6 ... peripheral wall 7 ... lower part of electrolyte flow 8 ... cylindrical ring 9 ... groove 10 ... safety valve 11 ... rubber-like elastic body 12 ... lead 13 ... L-shaped bent part 14 ... electrolyte 15 ... Stopper ridge 16: Outer ridge 17: Groove

Claims (6)

[Claims] 1. An electrode body (1) having a separator (1C) disposed between a positive electrode plate (1A) and a negative electrode plate (1B), and an outer can containing the electrode body (1). (2), a sealing body (3) that hermetically closes the opening of the outer can (2) via a gasket (4),
An insulating separator (5) disposed inside the outer can (2) and disposed between the electrode body (1) and the sealing body (3) to insulate the electrode body (1) and have an uneven upper surface. A battery comprising: 2. The insulating separator (5) has a surface roughness of 0.
The battery according to claim 1, wherein the rough surface has an uneven surface on an upper surface of 35 or more. 3. The battery according to claim 1, wherein the insulating separator (5) is provided with a radial groove (17) on the upper surface to form an uneven surface. 4. The battery according to claim 1, wherein the insulating separator (5) is a molded plastic body, the upper surface of which is molded into an uneven surface. 5. The battery according to claim 1, wherein the upper surface of the insulating separator is coated with a hydrophilic film. 6. An outer can (2) having a peripheral wall (6) protruding from the inner surface along an upper edge of the electrode body (1), and insulating between the electrode body (1) and the peripheral wall (6). The battery according to claim 1, wherein a separator (5) is provided.