JPH11149908A - Battery and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten the capacity of a battery, which comprises a bottomed cylindrical outer can and power generating elements built in the can, by increasing the inside volume of the battery in spite of the regulated battery size as compared with a conventional one. SOLUTION: A positive electrode can 1 has a bottomed cylindrical shape made of a steel sheet 1a and is coated with a nickel coating layer 1b in the inner surface and an insulating resin layer 1c in the outer face. Printing is carried out on the insulating resin layer 1c. The positive electrode can 1 is produced by applying an insulating resin to a nickel-coated steel sheet, burning the insulating resin to give pre-coated steel sheet and forming the resultant pre-coated steel sheet into a bottomed cylindrical shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery in which a power generation element is built in a terminal / outer can made of a nickel-plated steel plate or a stainless steel plate.

[0002]

2. Description of the Related Art Conventionally, most of primary and secondary batteries such as an alkaline manganese battery, a lithium battery, and a nickel cadmium battery are provided with a cylindrical or square metal outer can having a bottom and a power generating element. The positive electrode and the negative electrode are built in via a separator, and the opening is sealed with a sealing body. The outer can also serves as a positive electrode terminal or a negative electrode terminal, and an insulating shrink label or an insulating shrink tube is wound around the outer circumference of the outer can to be insulated.

[0003] Insulation shrink labels are described in detail in, for example, Japanese Patent Publication No. 7-54696, but are generally a PVC film or a PE with a pressure-sensitive adhesive.
It is made of a T film, the label length is set slightly longer than the outer circumference of the outer can, and the label is attached to the outer circumference of the outer can with the ends of the label overlapped. Many of these labels are printed for decoration and display, and are coated with aluminum to give metallic luster. In the label, the thickness of the film itself is 40 to 60 μm, but the total thickness including the thickness of the pressure-sensitive adhesive is about 60 to 90 μm.

[0004] In general, in both primary batteries and secondary batteries, there is a great demand for higher capacity of the batteries, and research for that purpose is being actively conducted. In order to increase the capacity of the battery, it is important to improve the energy density of the power generating element and to make the separator thinner. It is also effective to make the volume of the as large as possible.

[0005]

In order to increase the volume of the outer can, the size of the outer can can be increased.
Since the outer diameter and height range of the battery are determined by standards, in the case of a battery with an insulating shrink label attached to a cylindrical outer can as described above, the outer diameter of the outer can is the outer diameter of the battery It must be set to a range obtained by subtracting the thickness of the label (equivalent to the thickness of three labels including the overlap of the labels) from the standard value of.

For example, in the case of an AA alkaline manganese battery (LR6), the outer diameter of the battery is determined according to Japanese Industrial Standard (JI).
In S), the thickness is set in the range of 13.5 mm to 14.5 mm. Therefore, at the time of actual battery production, the thickness of three labels (240 μm when the thickness of the label is 80 μm).
The outer diameter of the metal outer can is 13.85 so that the outer diameter of the battery obtained by adding the above is within the range of 14.0 mm to 14.2 mm.
mm.

[0007] Therefore, it is an object to ensure as large a volume of the outer can as possible under the constraint that the battery size is determined by the standard. For such a problem, for example, in Japanese Patent Publication No. Hei 7-99686, in a bottomed cylindrical outer can made of a nickel-plated steel plate, the thickness of the steel plate and the thickness of the nickel plating layer are set as follows.
It is disclosed that the inner volume of the battery can be increased and the battery capacity can be increased by forming the battery to be thinner at the side portions than at the bottom portion. However, a technique effective for further increasing the capacity is desired.

In view of the above-mentioned problems, the present invention provides a battery in which a power generating element is incorporated in a bottomed cylindrical outer can, while satisfying the battery size, while increasing the internal volume of the battery as compared with the related art. The purpose is to realize a high capacity battery.

[0009]

In order to achieve the above object, according to the present invention, an outer can for accommodating a power generating element is provided on an outer peripheral surface of a steel plate molded into a bottomed cylindrical shape by baking and coating an insulating resin layer. Was formed. According to this configuration, the outer peripheral surface of the steel plate molded into a bottomed cylindrical shape is insulated by the insulating resin layer instead of the conventional insulating shrink label or insulating shrink tube. Since the thickness of the insulating resin layer can be considerably reduced as compared with the insulating shrink label or the insulating shrink tube, the outer diameter of the main body of the outer can made of a steel plate can be set accordingly.

Therefore, without changing the size of the battery,
The inner volume of the outer can can be increased as compared with the conventional case, and the capacity of the battery can be increased. In particular, the present invention can be easily applied to a battery in which an outer can is formed into a bottomed cylindrical shape and an opening is sealed with a sealing body, and is effective. It is also possible to print on the surface of the insulating resin layer.

The thickness of the insulating resin layer is 3 μm to 10 μm
If it is set to a relatively small range, the insulating resin layer hardly peels off, and the size of the main body of the outer can made of a steel plate can be set large, which is desirable for increasing the capacity of the battery. The battery having the above-described structure is formed by forming an insulating resin layer by baking coating on one side of a steel sheet to form a pre-coated steel sheet, and molding the pre-coated steel sheet into a bottomed tubular shape such that the insulating resin layer is on the outside. , The power generation element is housed in the outer can, and the opening of the outer can is sealed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Structure of Battery] FIG. 1 is a sectional view of a cylindrical alkaline manganese battery according to one embodiment of the present invention. As shown in this figure, this alkaline manganese battery 10 is such that a positive electrode 2 having a cylindrical shape with a bottom and a negative electrode 3 as a power generating element and a separator 4 for separating the same are filled in a positive electrode can 1 having a bottom. Is sealed with a disk-shaped sealing body 5.

In the positive electrode can 1, a steel plate 1a molded into a bottomed cylindrical shape is covered with a nickel plating layer 1b on the inner surface and an insulating resin layer 1c on the outer peripheral surface. The surface of the insulating resin layer 1c is printed. Also,
In the center of the bottom of the positive electrode can 1, a protrusion 1d serving as a positive electrode terminal is formed.

The positive electrode 2 is constituted by a pellet formed by press-molding a positive electrode mixture in which manganese, graphite and the like are mixed into a donut shape. The negative electrode 3 is a mixture of zinc powder, a gelling agent, and the like.
Is filled through. The separator 4 includes a cylindrical side plate 4a and a circular bottom plate 4b. The separator 4 is made of a separator base paper mainly composed of polyvinyl alcohol, and is impregnated with an alkaline electrolyte.

The sealing body 5 is a disk-shaped member made of an insulating material (nylon 66), and is inserted into the opening of the positive electrode can 1 to seal it. A notch 5a serving as a safety valve is formed in the sealing body 5. This sealing body 5
A disc-shaped negative electrode terminal plate 6 is attached to the outer surface of
A nail-shaped negative electrode current collector 7 is inserted into the center of the sealing body 5. In the negative electrode current collector 7, the needle 7 a is inserted into the negative electrode 3 through the sealing body 5, and the head 7 b is fixed to the negative electrode terminal plate 6.

The edge of the positive electrode can 1 is crimped to the outer peripheral portion of the negative electrode terminal plate 6, and the outer peripheral portion of the sealing body 5 is interposed therebetween so that the positive electrode can 1 and the negative electrode terminal plate 6 are inserted. Is insulated from [Method of Manufacturing Battery] A method of manufacturing the alkaline manganese battery 10 will be described below.

Production of Positive Electrode Can 1 The positive electrode can 1 is produced by molding a precoated steel sheet obtained by baking and coating an insulating resin on a nickel-plated steel sheet into a cylindrical shape with a bottom. The details will be described below with reference to FIGS. FIG. 2 is a diagram illustrating a process of baking and coating an insulating resin on a nickel-plated steel plate.

In FIG. 1, a nickel-plated steel sheet 11
Is a steel plate having a thickness of about 0.25 mm and a nickel plating layer formed with a thickness of about 2 μm,
It is wound in a roll. This nickel-plated steel sheet 11
Then, a precoat paint 13 is applied using a roll coater 12 and passed through a baking furnace 14 to produce a precoated steel sheet 15.

As the resin for the precoat paint, thermosetting resins such as polyester resin, epoxy resin, acrylic resin, and alkyd resin used for ordinary precoated steel sheets can be used. In particular, polyester resin and epoxy resin Is preferred. In many cases, the outer peripheral surface of the positive electrode can 1 needs to be colored for decoration. In this case, a kneaded dye or color pigment of a desired color is used as a precoat paint. .

The thickness of the coating film to be applied is set so that the film thickness after baking falls within the range of 3 μm to 50 μm, but it is better to set the thickness within a relatively small range (3 μm to 10 μm). This is preferable in that the occurrence of peeling of the coating film during the drawing process can be reduced. In FIG. 2, the precoating paint 1 is applied by the roll coater 12.
3 is applied once, but two or more coats may be applied.

In the baking furnace 14, a baking temperature of 200
Baking is performed at about 250 ° C. for about 20 to 30 seconds.
Then, after leaving the baking furnace 14, the precoated steel sheet 15 is produced by cooling. The precoated steel sheet 15 is once wound into a roll as shown in FIG. Next, using the pre-coated steel sheet 15 thus manufactured, it is punched into a disk shape, and subjected to transfer drawing to be molded into a bottomed cylindrical shape, thereby manufacturing the positive electrode can 1.

FIG. 3 is a view showing a state when a disk-shaped precoated steel sheet is subjected to transfer drawing. In this transfer drawing, as described in JP-B-7-99686, a steel plate is subjected to drawing and ironing stepwise using a punch and an ironing die.

That is, a disk-shaped precoated steel plate (blank) as shown in FIG. 3A is bent at the outer periphery as shown in FIG. 3B, and is drawn down deeply as shown in FIG. 3C. Then, a convex portion serving as a terminal is formed on the bottom as shown in FIG. 3D, and the edge is bent. As shown in FIG.
Perform drawing and ironing. With such drawing and ironing, the pre-coated steel sheet is partially stretched,
Since the insulating resin layer on the surface of the steel sheet is firmly adhered to the steel sheet by baking, it is stretched following the elongation of the steel sheet.

Further, the bottom is molded as shown in FIG. 3 (f), and the bent portion at the edge is cut as shown in FIG. 3 (g), whereby the positive electrode can 1 is manufactured. The protrusion 1
Since d is a positive electrode terminal, its surface needs to be conductive. Therefore, the surface of the protrusion 1d is polished to scrape off the insulating resin layer. Filling of Positive Electrode Can 1 with Power Generating Element, etc. FIG. 4 is a diagram illustrating a process of filling the positive electrode can 1 with a power generating element, etc., and sealing the same.

As shown in FIG. 4A, the positive electrode 2 is filled by storing three donut-shaped positive pellets in the prepared positive electrode can 1 side by side. Then, the side plate 4a and the bottom plate 4b of the separator 4 are mounted in the hollow portion of the positive electrode 2. Next, as shown in FIG. 4B, an alkaline electrolyte is injected into the inside of the
Is impregnated with the alkaline electrolyte. Then, the inside of the separator 4 is filled with a slurry made of a zinc powder as a negative electrode material and a gelling agent to form the negative electrode 3.

Sealing the opening of the positive electrode can 1 As shown in FIG. 4 (c), the positive electrode can 1
Is processed to form a seam groove 1e, and the sealing body 5 is formed.
Stuff. Then, the negative electrode current collector 7 to which the negative electrode terminal plate 6 is attached is inserted into the negative electrode 3 through the sealing body 5.
As shown in FIG. 4D, the edge of the positive electrode can 1 is inserted between the edge of the positive electrode can 1 and the outer edge of the negative electrode terminal plate 6 with the outer edge of the sealing body 5 interposed therebetween. The part is crimped to the outer peripheral part of the negative electrode terminal plate 6.

Printing on Outer Peripheral Surface of Positive Electrode Can 1 On the outer peripheral surface of the positive electrode can 1 of the assembled battery (that is, the surface of the insulating resin layer 1c), characters, designs, and the like are printed by a printing machine.
This printing can be basically performed by the same method as the method of printing on the outer peripheral surface of the can for drinking water.

That is, the assembled battery is mounted on a printing machine, and ink is printed on the outer peripheral surface of the battery from the plate via a transfer roll. As the type of plate used in the printing press,
Examples include lithographic, gravure, letterpress, and flexographic. According to the above-described manufacturing method, in the step, since the positive electrode can 1 is manufactured using the precoated steel sheet, the positive electrode can 1 can be manufactured continuously and relatively easily, which is advantageous in cost. It is.

In the above battery manufacturing method, as a method for manufacturing a positive electrode can having an insulating resin layer formed on the surface, first, a paint is applied to a nickel-plated steel plate by baking and painting, and a precoated steel plate is formed. Although a method of processing was used, the method is not necessarily limited to this method. First, a nickel-plated steel sheet is drawn and formed into a positive electrode can, and a paint is applied on the outer peripheral surface thereof (for example, by spraying the surface of the positive electrode can by spraying). By coating and baking), a positive electrode can having an insulating resin layer formed on the surface can be produced.

In the present embodiment, the battery in which the outer can also serves as the positive electrode terminal has been described. However, the present invention can be similarly applied to a battery in which the outer can also serves as the negative electrode terminal. Further, in the present embodiment, an example in which a nickel-plated steel plate is used as a material for the outer can is shown, but the same can be applied to a case where a stainless steel plate or the like is used.

In this embodiment, a cylindrical alkaline manganese battery has been described as an example. However, the present invention relates to a battery in which a power generation element is built in a cylindrical outer can, such as a cylindrical or rectangular tube. If there is, it can be widely applied to all types of batteries including primary batteries and secondary batteries, including lithium batteries and nickel cadmium batteries.

[0032]

EXAMPLE An LR6 type battery was manufactured based on the above embodiment. The conditions for producing the precoated steel sheet are as follows. Nickel plated steel sheet is 0.25 thick
mm. A polyester resin was used as the resin of the precoat paint.

The baking was passed through a heating furnace at about 250 ° C. for 30 seconds. The thickness of the insulating resin layer in the precoated steel sheet is 2 μm, 6 μm, 7 μm, 10 μm, 15 μm,
Each value was set to 20 μm. Then, using each of the pre-coated steel sheets manufactured as described above, transfer drawing was performed to manufacture a positive electrode can.

The size of the positive electrode can is 48 mm high,
The outer diameter of a was set to be 14.0 mm. Then, a battery was assembled using each of the prepared positive electrode cans, and the surface thereof was printed by a lithographic printing method. All the batteries of the examples manufactured in this manner have outer diameters of 14.0 mm to 1 mm.
It entered the range of 4.2 mm.

The outer diameter (14.0) of the steel plate of the positive electrode can of the present embodiment.
mm) is 0.15 mm larger than the outer diameter (13.85 mm) of the steel plate of the positive electrode can when the above-described conventional insulating shrink label is used. This means that the internal volume is 2.2%
This corresponds to an increase. In addition, when the state of the insulating resin layer was observed in each of the batteries manufactured as described above, when the thickness of the insulating resin layer was 2 μm, 6 μm, and 7 μm, the coating film was not peeled off and was in a good state. Yes, film thickness 1
With the film thicknesses of 0 μm, 15 μm and 20 μm, slight peeling of the coating film was observed.

From this, it is understood that it is preferable to set the film thickness of the insulating resin layer to a relatively small value (10 μm or less) since the peeling of the coating film does not easily occur.

[0037]

As described above, according to the present invention, an outer can for accommodating a power generating element has a structure in which an insulating resin layer is formed by baking coating on an outer peripheral surface of a steel plate molded into a bottomed cylindrical shape. Thus, without changing the size of the battery, the internal volume of the battery can be increased as compared with those using a conventional insulating shrink label or insulating shrink tube, and a higher capacity of the battery can be realized.

In particular, the present invention can be easily applied to a battery in which an outer can is formed into a cylindrical shape with a bottom and the opening is sealed with a sealing body, and is effective. It is also possible to print on the surface of the insulating resin layer. The battery having the above-described structure is formed by forming an insulating resin layer by baking coating on one side of a steel sheet to form a pre-coated steel sheet, and molding the pre-coated steel sheet into a bottomed tubular shape such that the insulating resin layer is on the outside. , The power generation element is housed in the outer can, and the opening of the outer can is sealed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cylindrical alkaline manganese battery according to an embodiment of the present invention.

FIG. 2 is a view showing a step of baking and coating an insulating resin on a nickel-plated steel sheet.

FIG. 3 is a view showing a state when transfer drawing is performed on a disc-shaped precoated steel sheet.

FIG. 4 is a diagram illustrating a process of filling a positive electrode can with a power generating element and the like and sealing the positive electrode can.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode can 1a Steel plate 1b Nickel plating layer 1c Insulating resin layer 2 Positive electrode 3 Negative electrode 4 Separator 5 Sealing body 6 Negative terminal plate 7 Negative current collector 7a Needle part 7b Head 10 Alkaline manganese battery 11 Nickel plated steel plate 12 Roll coater 13 Precoat paint 14 Furnace 15 Precoated steel sheet

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazuhiro Shikada 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Energy Tottori Co., Ltd.

Claims (7)

[Claims] 1. A battery comprising an outer can containing a power generating element, wherein an insulating resin layer is formed by baking coating on an outer peripheral surface of a steel plate molded into a bottomed cylindrical shape. 2. The outer can is molded into a bottomed cylindrical shape,
The battery according to claim 1, wherein the opening is sealed with a sealing body. 3. The printing method according to claim 1, wherein the surface of the insulating resin layer is printed.
The battery as described. 4. The insulating resin layer according to claim 1, wherein said insulating resin layer has a thickness of 3 μm to 10 μm.
The battery according to any one of the above. 5. A pre-coating step for forming a pre-coated steel sheet by forming an insulating resin layer on one side of a steel sheet by baking coating, and forming the formed pre-coated steel sheet into a bottomed cylindrical shape such that the insulating resin layer is on the outside. A method for manufacturing a battery, comprising: an outer can forming step of forming an outer can by using the above method; a power generating element storing step of storing a power generating element in the prepared outer can; and a closing step of closing an opening of the outer can. . 6. The method for manufacturing a battery according to claim 5, wherein in the step of forming the outer can, the precoated steel sheet is molded into a bottomed cylindrical shape. 7. The method for producing a battery according to claim 5, further comprising a printing step of performing printing on a surface of the outer can created in the outer can creating step.