JPH0773861A - Battery - Google Patents

Abstract

PURPOSE:To provide a battery at low cost, in which a cover is bonded to a container with sufficient strength resistant to the internal pressure, to enhance electrolyte leakage resistance. CONSTITUTION:A battery 1 is manufactured by accommodating a power generating element in a container 2 formed by deep drawing of a metal plate serving as an anode. A cover 4 connected to a cathode, made of a synthetic resin which adheres to metal when heated is heat-bonded to the opening of the container 2 through an undercoating resin layer 5 which is applied to the surface to be bonded. The synthetic resin is polyamide, and the undercoating resin layer 5 is formed with an epoxy-phenol resin composition prepared by mixing bisphenol type epoxy resin with resol type phenol resin in a weight ratio of 50/50-95/5. Surface treatment for increasing the adhesion of the undercoating resin layer 5 with the container 2 is conducted in the bonding region of the container 2, and the undercoating resin layer 5 is formed on the surface treatment layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention stores a power generating element in a container formed by deep-drawing a metal plate forming a cathode, and fits a synthetic resin lid provided with an anode in the opening of the container. It is related to the battery.

[0002]

2. Description of the Related Art Conventionally, a strong alkaline electrolyte and a power generating element such as a separator are housed in a container formed by deep-drawing a metal plate into a rectangular shape, and a metal lid is fitted in the opening of the container. A rectangular battery is known. In the prismatic battery, the container itself serves as a cathode, and the lid has an anode.

In the conventional prismatic battery, the internal pressure may reach 20 to 40 atm due to the electrolytic solution.
A metal lid is welded to the opening of the container. The anode is attached to the metal lid via an insulator, and the anode has an internal safety valve for releasing gas to the outside of the battery when the internal pressure becomes high as described above. It has a cap. Welding of the metal lid to the container opening is conventionally performed by numerically controlling a YAG laser.

However, when the metal lid is welded by the YAG laser, the electrolyte may leak if it is not precisely processed so that the shape of the metal lid matches the opening of the container. Also, there is a disadvantage that minute cracks are easily formed by welding, and the liquid leakage may occur from such cracks. Further, the YAG laser provided with the numerical control device is very expensive, and since it takes about 5 seconds to weld one piece, the manufacturing cost cannot be increased.

[0005]

SUMMARY OF THE INVENTION The present invention seeks to provide an improved battery.

More specifically, the object of the present invention is to eliminate such inconvenience, and the lid is adhered to the container with sufficient strength to withstand the internal pressure, which is excellent in liquid leakage resistance and is inexpensive to manufacture. An object is to provide a battery that can.

Another object of the present invention is to provide a battery having excellent lid bonding strength even after being stored for a long time in an alkaline environment.

[0008]

In order to achieve the above object, the battery of the present invention has a power generating element housed in a container formed by deep-drawing a metal plate forming a cathode, and the anode is provided at the opening of the container. In a battery having a lid fitted therein, the lid is made of a synthetic resin having adhesiveness when heated, and is heated through an undercoat resin layer applied to the opening of the container in an adhesive range. It is characterized by being fused.

Further, in the battery of the present invention, the lid body is made of a metal plate and a synthetic resin having an adhesive property when attached to the peripheral portion of the metal plate and heated, and adhered to the opening of the container. It is characterized in that it is heat-fused through the undercoat resin layer applied in the range.

When the lid body is made of the synthetic resin, the synthetic resin serves as an insulator, so that the anode is attached to the lid body without interposing an insulator. When the lid body is made of a metal plate and the synthetic resin attached to the peripheral portion of the metal plate, the anode is attached to the metal plate via an insulator.

The metal plate forming the cathode is SP
Cold rolled steel sheets such as CE, galvanized steel sheets such as SPGD and SPGDD, aluminum alloy sheets such as 5052 material and 7075 material, titanium alloy sheets such as titanium type 1 material and titanium type 2, S
Stainless steel plates such as US304 and SUS420 can be used. When using the SPCE steel plate, a SPCE steel plate having a nickel plating of 3 to 4 μm may be deep-drawn into a rectangular shape.
The E steel plate may be plated with 1 to 3 μm of nickel.

Further, in the battery of the present invention, the synthetic resin having adhesiveness to metal when heated is polyamide, and the undercoat resin layer is made of bisphenol type epoxy resin and resol type phenol resin at 50/50. ~ 9
It is characterized in that it is composed of an epoxyphenol resin-based composition obtained by mixing at a weight ratio of 5/5.

The polyamide used as the synthetic resin is, for example, a homopolyamide obtained from lactam or ω-aminocarboxylic acid, a copolyamide or a polyamide obtained by blending them, and a condensation of a dicarboxylic acid compound and a diamine compound. Examples thereof include homopolyamide, copolyamide obtained by a polymerization reaction, and polyamide obtained by blending them. As the former polyamide obtained from lactam or ω-aminocarboxylic acid, polyamides having 10 to 13 carbon atoms, nylon 12, nylon 11, etc. are particularly suitable. Further, as the polyamide obtained by the condensation polymerization reaction of the latter dicarboxylic acid compound and diamine compound,
Nylon 6,6 etc. are suitable.

The polyamide is further obtained by blending the various polyamides obtained from the former lactam or ω-aminocarboxylic acid with the various polyamideamides obtained by the condensation polymerization reaction of the latter dicarboxylic acid compound and diamine compound. It may also be a polyamide.

The undercoat resin layer is preferably a mixture of a bisphenol type epoxy resin and a resol type phenol resin in order to bond the polyamide and the metal plate forming the cathode by heating. When the weight ratio of the epoxy resin and the resol type phenol resin is less than 50/50, or 95
When it is larger than / 5, sufficient adhesive strength cannot be obtained.
Further, the bisphenol type epoxy resin has a number average molecular weight of 2000 to 1 in order to secure sufficient adhesive strength.
It is preferably in the range of 5000.

Further, when the battery of the present invention contains a strong alkaline electrolyte, the inside thereof is affected by the electrolyte and is in an alkaline environment. When the battery is stored for a long period of time in such an environment, the adhesiveness between the undercoat resin layer and the metal plate forming the cathode tends to be reduced due to the influence of the alkaline electrolyte.

Therefore, in the battery of the present invention, in order to maintain the adhesion between the undercoat resin layer and the metal plate in the alkaline environment for a long period of time, a surface treatment is applied to the bonding area of the metal plate. Is preferably provided. The surface treatment can be carried out by chemical conversion treatment of the surface of the metal plate with chromic acid, phosphoric acid or the like, and by the surface treatment, a chemical conversion of a chromium-chromate layer, a phosphoric acid chromate layer or the like on the surface of the metal plate. A treated coating is formed.

In the heat fusion, the lid is fitted into the opening of the container, and high-frequency heating or the like is performed in a state where the lid is bonded via the undercoat resin layer applied in the bonding area of the opening. It can be performed by heating with a heat source. When a heat source other than high-frequency heating is used, the lid may soften, so the lid is cooled immediately after heat fusion.

[0019]

According to the battery of the present invention, when the lid body is made of synthetic resin having adhesiveness when heated, when the lid body is fitted into the opening of the container, the lid body made of the synthetic resin is formed. It is pressure-bonded to the undercoat resin layer. Therefore, by heating in this state, the lid is easily and surely heat-sealed to the opening of the container through the synthetic resin that constitutes itself and the undercoat resin layer applied to the bonding area. Since the lid itself is made of the synthetic resin, it is possible to obtain sufficient resistance to the internal pressure of the battery by being bonded as described above.

Further, according to the battery of the present invention, when the lid is made of a metal plate and a synthetic resin which is attached to the peripheral portion of the metal plate and has adhesiveness when heated, the lid is a container. , The synthetic resin attached to the peripheral portion of the metal plate is pressure-bonded to the undercoat resin layer. Therefore,
By heating in this state, the lid is easily and reliably heat-sealed to the opening of the container via the synthetic resin and the undercoat resin layer applied to the bonding area. Since the lid is made of a metal plate and the synthetic resin attached to the peripheral portion thereof, the strength of the lid is reinforced by the metal plate,
Further excellent resistance to the internal pressure can be obtained.

Further, according to the battery of the present invention, the synthetic resin is polyamide, and the undercoat resin layer mixes the bisphenol type epoxy resin and the resol type phenol resin at a weight ratio of 50/50 to 95/5. When the epoxy phenolic resin composition described above is used, the adhesion between the undercoat resin layer and the synthetic resin and between the undercoat resin layer and the metal plate forming the cathode is improved by heating.

Further, according to the battery of the present invention, the metal plate forming the cathode is subjected to a surface treatment for improving the adhesion between the undercoat resin layer and the metal plate, so that the metal plate can be maintained in an alkaline environment for a long time. Even after being stored for a period of time, the adhesion between the undercoat resin layer and the metal plate is maintained.

[0023]

The battery of the present invention will now be described in more detail with reference to the accompanying drawings. FIG. 1 is an explanatory sectional view of a prismatic battery of this embodiment, and FIG. 2 is an explanatory sectional view of a prismatic battery of another embodiment.

As shown in FIG. 1, the prismatic battery 1 has 3 to 4 parts in advance.
A strong alkaline electrolyte in a rectangular metal container 2 formed by deep drawing a SPCE steel plate plated with 4 μm nickel into a rectangular shape,
A power generation element 3 such as a separator is housed, and a lid 4 made of synthetic resin is heat-sealed to the opening of the rectangular metal container 2 via an undercoat resin layer 5 applied in the adhesion range. The lid 4 is made of nylon 12, and the undercoat resin layer 5 is made of 70 parts by weight of a bisphenol A type epoxy resin having a number average molecular weight of 3750 and 30 parts by weight of a resol type bisphenol formaldehyde resin. In the rectangular metal container 2, a chromium-chromate layer (not shown) is formed by subjecting the bonding area to chemical conversion treatment with chromic acid, and the undercoat resin layer 5 is formed on the chromium-chromate layer. Has been done.

In the prismatic battery 1, the prismatic metal container 2 itself acts as a cathode, and the lid 4 is provided with the anode 6. Further, the anode 6 is provided with an anode cap (not shown) provided with a safety valve that releases gas when the internal pressure rises.

The prismatic battery 1 shown in FIG. 1 was manufactured as follows.

First, an SPCE steel plate having a nickel plating of 3 to 4 μm preliminarily was deep-drawn into a rectangular shape having a depth of 45.2 mm and an inner diameter of the opening of 4.8 mm × 15.59 mm. The rectangular metal container 2 was used. The corner of the opening is processed to R0.25.

Next, the opening of the rectangular metal container 2 was subjected to chemical conversion treatment over the entire inner surface to form a chromium chromate layer.
Next, the square metal container 2 is washed with water and dried, and 30 parts by weight of 70 parts by weight of the bisphenol A type epoxy resin having the number average molecular weight of 3750 and 30 parts by weight of the resol type bisphenol formaldehyde resin are provided on the chromium chromate layer. The solvent-based resin was applied and baked and dried at 210 ° C. for 10 minutes to form the undercoat resin layer 5 in the range where the lid 4 was bonded. Since the undercoat resin layer 5 serves as an insulator, if it is formed in an excessively large area other than the range where the lid 4 is bonded as described above, the function of the rectangular metal container 2 as a cathode may be hindered. Then, after the undercoat resin layer 5 is formed, the power generating element 3 is housed in the rectangular metal container 2.

Next, the lid 4 made of nylon 12 is fitted into the opening of the rectangular metal container 2. The lid 4 has a thickness of 3 mm
In anticipation of shrinkage due to heating of nylon 12,
It is formed to be 5/100 larger than the dimension of the opening. By doing so, the fitted lid body 4 is pressure-bonded to the opening of the rectangular metal container 2 through the undercoat resin layer 5, and when the lid body 4 is heat-sealed, the rectangular shape It is possible to avoid the formation of a gap between the metal container 2 and the lid 4, and it is possible to prevent the electrolyte from leaking.

Next, a high-frequency heating device is arranged around the opening of the rectangular metal container 2 to which the lid 4 is fitted and pressure-bonded via the undercoat resin layer 5 as described above, and the temperature is set to 230 ° C. for 1 hour. Heated for seconds. For the heating, the current of the high frequency heating device is set to 10
A, the voltage was 90 V with no load, and 110 V under load. The adhesive strength when the range of the lid body 4 heated to 230 ° C. is 8 mm from the upper edge of the rectangular metal container 2 is shown in Table 1 below.
Shown in. The adhesive strength was measured by the tensile peel strength immediately after adhesion and after storage for 6 months, and shown as an average value of 5 samples (Experimental Example 1).

Further, the prismatic battery 1 was manufactured in the same manner as described above, except that the opening of the prismatic metal container 2 was not subjected to the chemical conversion treatment and the chromium chromate layer was not formed. The heating was performed as shown in Table 1 with respect to the current of the high-frequency heating device, the voltage when no load was applied, and the voltage when the load was applied. Table 1 below shows the adhesive strength (Experimental Examples 2 to 5) when the range of the lid 4 heated to 230 ° C. was changed. Adhesive strength was measured by tensile peel strength immediately after adhesion and after storage for 6 months, and shown as an average value of 5 samples.

[0032]

[Table 1]

In order for the lid 4 to maintain the adhesion against the internal pressure, it is necessary that the tensile peel strength is 60 kg or more, but as is clear from Table 1, the lid of this embodiment is 4 has a tensile peel strength far exceeding 60 kg,
It is bonded with sufficient strength to resist the internal pressure. Further, by subjecting the area of the rectangular metal container 2 to which the lid body 4 is bonded to to the surface treatment, the tensile peel strength is maintained at the same level as immediately after bonding even after long-term storage in an alkaline environment. it is obvious.

Next, another embodiment will be described.

In the prismatic battery 11 shown in FIG. 2, the lid 4 has a metal plate 4a and an annular synthetic resin molded body 4 attached to the peripheral portion thereof.
b, and has the same configuration as the prismatic battery 1 shown in FIG. 1 except that the anode 6 is attached to the metal plate 4a via an insulator (not shown). The prismatic battery 11 has a lid 4
Is reinforced by the metal plate 4a, it is possible to sufficiently counter the rise in internal pressure.

The prismatic battery 11 is the prismatic battery 1 shown in FIG.
It is manufactured in the same manner as. The lid 4 can be manufactured, for example, by injection-molding a synthetic resin on the peripheral edge of the metal plate 4a to form the synthetic resin molding 4b.

In each of the above-described embodiments, the surface treatment of the rectangular metal container 2 is performed with chromic acid, but the same effect can be obtained by performing the chemical conversion treatment with phosphoric acid.

In each of the above-mentioned embodiments, the prismatic battery is described as an example, but the present invention can be applied to a so-called circular battery having a cylindrical shape.

[0039]

As is apparent from the above, according to the battery of the present invention, the synthetic resin forming the lid has adhesiveness to metal when heated, and therefore the lid is used as a container. By heating while fitted in the opening, heat fusion can be easily and reliably performed in the opening of the container via the undercoat resin layer. Therefore, Y equipped with a numerical controller
No need to use expensive equipment such as AG laser,
The manufacturing cost can be reduced.

Further, according to the battery of the present invention, since the lid is fitted and pressure-bonded to the opening of the container by the flexible synthetic resin, the lid does not need to be precisely processed, and the electrolytic solution is not required. It is possible to prevent liquid leakage.

Further, according to the battery of the present invention, since the lid itself is made of the synthetic resin, it is possible to sufficiently counter the internal pressure of the battery. Further, when the lid body is made of a metal plate and the synthetic resin attached to the peripheral portion thereof, the strength of the lid body is reinforced by the metal plate, so that the resistance to the internal pressure can be further improved. it can.

Further, according to the battery of the present invention, the synthetic resin is polyamide, and the undercoat resin layer mixes the bisphenol type epoxy resin and the resol type phenol resin in a weight ratio of 50/50 to 95/5. Particularly excellent adhesive strength can be obtained when the epoxy phenol resin composition is formed.

Furthermore, according to the battery of the present invention, by subjecting the metal plate forming the cathode to a surface treatment for improving the adhesion between the undercoat resin layer and the metal plate, the metal plate is treated for a long time in an alkaline environment. Even after storage, the adhesion between the undercoat resin layer and the metal plate is maintained, and excellent adhesive strength can be obtained.

[Brief description of drawings]

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

FIG. 2 is an explanatory cross-sectional view of another embodiment of the battery according to the present invention.

[Explanation of symbols]

1 ... Battery, 2 ... Container, 3 ... Power generating element, 4 ... Lid,
4a ... Metal plate, 4b ... Synthetic resin, 5 ... Undercoat resin layer, 6 ... Anode.

Claims (4)

[Claims] 1. A battery in which a power generation element is housed in a container formed by deep-drawing a metal plate forming a cathode, and a lid having an anode is fitted in an opening of the container, wherein the lid is heated. A battery, which is made of a synthetic resin having an adhesive property when exposed to heat and is heat-sealed via an undercoating resin layer applied to the opening of the container in the adhesion range. 2. A battery in which a power generation element is housed in a container formed by deep-drawing a metal plate forming a cathode and a lid having an anode is fitted in an opening of the container, wherein the lid is made of metal. A plate and a synthetic resin that is attached to the peripheral edge of the metal plate and has adhesiveness when heated, and is heat-sealed via an undercoat resin layer applied to the opening of the container in the adhesion range. A battery characterized by being. 3. An epoxyphenol resin composition in which the synthetic resin is polyamide and the undercoat resin layer is a mixture of a bisphenol type epoxy resin and a resole type phenol resin in a weight ratio of 50/50 to 95/5. The battery according to claim 1, wherein the battery is made of a material. 4. The surface treatment for maintaining the adhesion between the undercoat resin layer and the metal plate in an alkaline environment in the bonding area of the metal plate forming the cathode. The battery according to any one of claims 1 to 3.