JP2007005157A - Plated steel sheet for battery container, battery container using the plated steel sheet for battery container, battery using the battery container, and method for producing plated steel sheet for battery container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a battery performance while reducing a liquid leakage due to gas generation accompanying an improvement in the battery performance, a battery container using the plated steel sheet for the battery container, and A battery using the battery container and a method for producing a plated steel sheet for the battery container are provided.
SOLUTION: By applying a nickel-titanium alloy plating directly on a steel plate through a nickel plating layer on the side that becomes the battery container inner surface of the steel plate, and then applying tin plating thereon, a heat treatment is performed, A metal layer containing titanium, nickel, and tin is formed on the outermost surface to form a plated steel sheet for battery containers, which is formed into a battery container and applied to the battery.
[Selection] Figure 1

Description

  The present invention relates to a plated steel sheet for battery containers, a battery container using the plated steel sheet for battery containers, a battery using the battery container, and a method for producing a plated steel sheet for battery containers.

  In recent years, with the development of portable AV equipment and mobile phones such as digital cameras, CD players, MD players, liquid crystal televisions, game machines, etc., alkaline batteries as primary batteries and nickel metal hydride batteries as secondary batteries as heavy load operating power sources Lithium ion batteries are often used. These batteries are required to have higher performance such as higher output and longer life, and battery containers filled with positive and negative electrode active materials are also required to improve performance as important components of the battery. Yes. Conventionally, as these battery container materials, in order to make it possible to maintain corrosion resistance against a strong alkaline electrolyte and low contact resistance at the interface between the inner surface of the battery container and the positive electrode mixture, nickel plating is applied to the cold-rolled steel sheet in advance. A formed nickel-plated steel sheet is formed into a battery container, or a cold-rolled steel sheet is formed into a battery container, and then the inner and outer surfaces of the battery container are nickel-plated by barrel plating. In addition, as nickel-plated steel sheets, in order to improve the adhesion between the nickel-plated layer and the steel substrate and to suppress the exposure of iron during the forming process, heat treatment is performed after nickel plating, and iron is interposed between the steel substrate and the nickel-plated layer. -Although the thermal diffusion treatment method provided with a nickel alloy layer (diffusion layer) is adopted, if the nickel layer remains on the outermost layer when forming the diffusion layer by heat treatment, the surface of the nickel layer is solid In order to inhibit the contact resistance due to the presence of an oxide film, a method of converting the entire nickel layer into an iron-nickel alloy layer (diffusion layer) has been proposed (for example, see Patent Document 1). In addition, hard gloss nickel plating with an organic brightener added to the inner surface of the battery container causes wedge-shaped cracks during press molding, increasing the positive electrode mixture and adhesion, and increasing the contact area. A method for reducing the internal resistance of the battery has been proposed (see, for example, Patent Document 2). Furthermore, the present inventors use a steel plate in which a nickel-tin alloy layer is formed on a nickel layer or an iron-nickel alloy layer (diffusion layer), so that fine cracks are not formed when the battery container is formed. A method has been proposed in which an uneven surface is formed on the inner surface of a battery container to reduce the internal resistance of the battery by increasing the contact area with the positive electrode mixture or the conductive coating (see, for example, Patent Document 3).

  When cracking occurs in the plating layer on the inner side of the battery container when the battery container is formed by drawing or ironing, the steel substrate is locally exposed. When the steel substrate is exposed, the exposed part comes into direct contact with a strong alkaline electrolyte, and in the vicinity of the steel plate substrate, nickel of the nickel plating layer, which is a noble metal than iron, manganese dioxide of active material, and oxygen are present. Therefore, iron dissolution occurs. When the eluted iron ions move to the negative electrode made of zinc, hydrogen gas is generated by reaction with the zinc. The gas generated in this way increases the battery internal pressure and causes leakage. Further, it is known that the battery performance is better as the thickness of the nickel plating layer is thinner. However, the degree of exposure of the steel base is increased, and there is a problem that the liquid leakage due to gas generation increases. In addition, as described in Patent Document 2 and Patent Document 3, when the plating film is hardened, the discharge characteristics are improved, but when the battery container is formed, cracks reaching the steel base are induced. The risk of increasing gas generation is increased.

Prior art document information relating to the present application includes the following.
Japanese Patent Application Laid-Open No. 08-017406 Japanese Patent Publication No. 2810257 Japanese Patent No. 2877957

  In the present invention, a method of improving the battery characteristics by reducing the plating thickness of the nickel-plated steel sheet, or a microcrack when forming a hard plating layer and heat-treating the plating film to form a battery container by heat treatment after plating. In conventional methods, such as improving the battery performance by increasing the adhesion with the positive electrode active material, while maintaining the improvement in battery performance, the liquid leakage due to gas generation associated with these methods is maintained. The purpose is to reduce.

In order to achieve the object of the present invention, the plated steel sheet for battery containers of the present invention is characterized in that a metal layer containing titanium, nickel, and tin is formed on the steel sheet on the side that is the battery container inner surface of the steel sheet. A plated steel sheet for battery containers (Claim 1);
In the plated steel sheet for battery containers of the above (Claim 1), an iron-nickel-titanium alloy layer and a nickel-titanium-tin alloy layer are formed in this order from the steel sheet side that is the inner surface of the battery container. Item 2), or an iron-nickel-titanium alloy layer, an iron-nickel-titanium-tin alloy layer are sequentially formed from the side of the steel plate that is the inner surface of the battery container (Claim 3), or An iron-nickel-titanium alloy layer, a nickel-titanium alloy layer, a nickel-titanium-tin alloy layer are formed in order from the steel sheet side on the side that becomes the battery container inner surface (Claim 4), or the battery container inner surface of the steel sheet An iron-nickel alloy layer, a nickel layer, a nickel-titanium-tin alloy layer are formed in order from the steel plate side of the steel plate (Claim 5), or from the steel plate side of the steel plate inside the battery container. An iron-nickel alloy layer, a nickel-titanium-tin alloy layer (Claim 6), or an iron-nickel alloy layer, iron-nickel- A titanium alloy layer, a nickel-titanium alloy layer, and a nickel-titanium-tin alloy layer are formed (claim 7).

Moreover, the battery container of the present invention is a battery container (Claim 8) formed by processing the plated steel sheet for a battery container according to any of the above (Claims 1 to 7) into a bottomed cylindrical shape,
The battery of the present invention is a battery (invention 9) using the battery container of the above (invention 8).
Furthermore, the method for producing a plated steel sheet for battery containers according to the present invention includes performing nickel-titanium alloy plating on at least the inner surface of the battery container and then tin-plating the upper layer, followed by heat treatment. A method for producing a plated steel sheet for battery containers (Claim 10), or nickel plating on at least the side of the steel sheet that is the inner surface of the battery container, followed by nickel-titanium alloy plating on the upper layer, and then the upper layer A method for producing a plated steel sheet for battery containers, characterized in that a heat treatment is performed after tin plating.

  The plated steel sheet for battery containers of the present invention is obtained by performing nickel-titanium alloy plating directly on the steel sheet through a nickel plating layer on at least the battery container inner surface, and then performing tin plating thereon. By applying heat treatment, a metal layer containing titanium, nickel, and tin, that is, a nickel-titanium-tin alloy layer is formed on the outermost surface. This metal layer is hard, and when the plated steel sheet is formed into a battery container, fine cracks are generated and the adhesion with the positive electrode mixture is improved, so that excellent discharge characteristics can be obtained even after long-term storage. Further, since titanium has a lower potential than iron, dissolution of iron can be suppressed by sacrificial dissolution of titanium. Therefore, even if the plating film on the steel plate is thin, or the pinhole of the plating layer or the hard plating layer is formed, a microcrack is generated and the steel substrate is exposed. Gas generation is reduced, leakage resistance is improved, and even though the battery discharge performance is excellent, the leakage resistance is inferior, and the problems in the conventional method of forming a hard nickel-plated steel sheet into a battery container can be solved. .

  The contents of the present invention will be described below. As a steel plate used as the substrate of the plated steel plate for battery containers of the present invention, low carbon aluminum killed steel for drawing (carbon content 0.01 to 0.15% by weight), or deep drawing for adding niobium or titanium. Non-aging ultra-low carbon aluminum killed steel (carbon content less than 0.01% by weight) is used. These steel hot-rolled plates are pickled to remove surface scales, then cold-rolled by a conventional method, and then subjected to electrolytic cleaning, annealing, and temper rolling as a substrate. Alternatively, an unannealed material after cold rolling and then electrolytically cleaning can be used as a substrate.

First, nickel plating is performed on one surface of the steel plate serving as the plating substrate, which is the inner surface of the battery container, and then nickel-titanium alloy plating is performed thereon. Alternatively, nickel-titanium alloy plating is performed directly on the steel plate. When nickel plating is performed, it is preferable to perform matte nickel plating using a Watt bath or semi-bright nickel plating using a plating bath obtained by adding an organic additive to the Watt bath. The adhesion amount of nickel plating is preferably ² g / m ² . If it is less than 2 g / m ² , pinholes are liable to occur, and the steel substrate is exposed excessively due to wrinkles generated when the battery container is molded. Even if nickel-titanium alloy plating is applied to the upper layer, titanium It becomes difficult to suppress the dissolution of iron ions in the alkaline electrolyte due to the sacrificial dissolution. The upper limit of the nickel plating adhesion amount can be appropriately determined depending on economy. Subsequent to the nickel plating or directly on the steel plate, nickel-titanium alloy plating is performed. As a nickel-titanium alloy plating bath, it is possible to use a plating bath in which potassium titanium fluoride is used as an ion source of titanium, nickel sulfate, and an organic complexing agent such as an amino acid such as glycine is added as a complexing agent. preferable. The amount of nickel-titanium alloy plating is preferably in the range of 0.1 to 1.0 g / m ² . If the amount is less than 0.1 g / m ² , the effect of suppressing iron dissolution of the exposed steel base due to the sacrificial dissolution of titanium is small. On the other hand, if the amount exceeds 1.0 g / m ² , the effect of suppressing iron dissolution reaches saturation. Become uneconomical. In nickel-titanium alloy plating, an alloy plating film having a titanium content of 10 to 30% is obtained depending on the plating bath composition to be applied, electrolysis conditions, bath pH, and the like.

Subsequent to the nickel plating, or after the nickel-titanium alloy plating is directly applied on the steel plate, the tin plating is performed. The amount of tin plating is preferably in the range of 0.5 to 5.0 g / m ² . If it is less than 0.5 g / m ² , the thickness of the nickel-titanium-tin alloy layer formed by the heat treatment is thin, and fine cracks are not generated sufficiently when being molded into the battery container, which is sufficient with the positive electrode active material. Adhesiveness cannot be obtained, and the battery discharge characteristics cannot be sufficiently improved. On the other hand, if it exceeds 5.0 g / m ² , the thickness of the nickel-titanium-tin alloy layer becomes excessively thick, and fine cracks that reach the steel sheet substrate are formed excessively when being formed into a battery container. As a result, the amount of gas generated in the battery container becomes great, and the leakage resistance of the electrolyte solution becomes inferior. The amount of tin plating is preferably such that all tin is consumed in the production of the nickel-tin intermetallic compound (Ni ₂ Sn) in relation to the nickel plating adhesion amount of the lower layer.

After nickel-titanium alloy plating and then tin plating, heat treatment is performed to form a nickel-titanium-tin alloy layer on the outermost surface. The heat treatment conditions include a heating temperature of 500 to 600 ° C. and a heating time of 4 to 12 hours when using the box annealing method, and a heating temperature of 650 to 800 ° C. and a heating time of 1 to 5 minutes when using the continuous annealing method. It is preferable that In selecting the heat treatment conditions, all the tin is converted into a nickel-tin intermetallic compound (Ni ₂ Sn). Conditions under which a tin-rich nickel-tin intermetallic compound (Ni ₂ Sn ₂ , Ni ₂ Sn ₄ ) is produced are undesirable because tin is eluted into the alkaline electrolyte and deteriorates battery performance.

  As shown above, it is shown in FIG. 1 to FIG. 6 by performing nickel plating on the steel sheet or by directly applying nickel-titanium alloy plating on the steel sheet and then performing tin plating and then heat treatment. A plated steel sheet for battery containers having such a layer structure is obtained.

  The battery container of the present invention is obtained by subjecting the above-described plated steel sheet for a battery container to a drawing process, a drawing ironing process (DI processing method), a drawing stretch processing method (DTR processing method), or a drawing process as a stretching process. It is obtained by forming into a bottomed cylindrical shape using the processing method used in combination. As the cylindrical shape, the bottom surface is a circle, an ellipse, or a polygonal shape such as a rectangle or a square, and is molded into a cylindrical shape with the side wall height appropriately selected according to the application. The battery container thus obtained is filled with a positive electrode mixture, a negative electrode active material, and the like to obtain a battery.

Hereinafter, the present invention will be described in detail with reference to examples.
[Creation of plated steel sheets for battery containers]

A hot rolled sheet of the above steel grade I or II is subjected to cold rolling and electrolytic cleaning by a conventional method to obtain a cold rolled sheet having a thickness of 0.25 mm. The following various types of plating are applied to an annealed plate that has been subjected to annealing at a soaking temperature of 640 to 680 ° C. for 8 hours using a method, and the plating is used as it is, or after plating, using a box-type annealing method. Heat treatment was applied at ˜550 ° C. and an overheating time of 6 to 8 hours. In the case of steel type II, the following various plating was performed on the unannealed plate that had been subjected to electrolytic cleaning, and then heat treatment was performed at a heating temperature of 750 ° C. and a heating time of 2 minutes by a continuous annealing furnace method. Thus, the plated steel sheet for battery containers was produced through the process shown to following (i)-(g).
B) Low carbon aluminum killed steel (I) → Cold rolling → Electrolytic cleaning → Annealing (box annealing method) → Temper rolling → Nickel plating (inside and outside) → Nickel-titanium alloy plating (inside) → tin plating (Inner side) → Heat treatment (box annealing method) → Temper rolling b) Low carbon aluminum killed steel (I) → Cold rolling → Electrolytic cleaning → Annealing (box annealing method) → Temper rolling → Nickel plating (outer surface) → Nickel-titanium alloy plating (inner side) → Tin plating (inner side) → Heat treatment (box annealing method) → Temper rolling c) Extremely low carbon aluminum killed steel (II) → Cold rolling → Electrolytic cleaning → Nickel plating ( Inner and outer surfaces) → Nickel-titanium alloy plating (inner surface side) → Tin plating (inner surface side) → Heat treatment (continuous annealing method) → Temper rolling d) Low carbon aluminum killed steel (I) → Cold rolling → Electrolytic cleaning → Annealing (Box annealing method) → Temper rolling → Nickel plating Inner and outer surfaces) → Tin plating (inner surface side) → Heat treatment (box annealing method) → Temper rolling e) Low carbon aluminum killed steel (I) → Cold rolling → Electrolytic cleaning → Annealing (box annealing method) → Adjustment Rolling → Nickel plating (inside and outside) → Heat treatment (box annealing method) → Temper rolling f) Low carbon aluminum killed steel (I) → Cold rolling → Electrolytic cleaning → Annealing (box annealing method) → Tempering Rolling → Nickel plating (inside and outside)
G) Ultra-low carbon aluminum killed steel (II) → Cold rolling → Electrolytic cleaning → Nickel plating (inner and outer side) → Tin plating (inner side) → Heat treatment (continuous annealing method) → Temper rolling Each plating process in this step was performed under the following conditions.

<Nickel plating>
Bath composition Nickel sulfate 300g / L
Nickel chloride 35g / L
Boric acid 40g / L
Bit inhibitor (sodium lauryl sulfate) 0.4mL / L
Anode Nickel beret (titanium basket filled with S pellets manufactured by INCO)
Equipped with polypropylene anode bag)
Stirring air stirring
pH 4.0-4.6
Bath temperature 55-60 ° C
Current density 10A / dm ²

<Nickel-titanium alloy plating>
Bath composition Nickel sulfate 8g / L
Potassium fluoride titanium 24g / L
L-glutamic acid 8g / L
Glycine 10g / L
Anode Nickel Beret (titanium basket filled with INP CO. S pellets)
Equipped with polypropylene anode bag)
Stirring air stirring
pH 5.0-5.5
Bath temperature 55-60 ° C
Current density 5A / dm ²

<Tin plating>
Bath composition Stannous sulfate 30g / L
Phenolsulfonic acid 60g / L
Ethoxylated α-naphthol 5g / L
Anode Tin plate Agitating Circulation of plating bath Bath temperature 45-50 ° C
Current density 5A / dm ²

  After the above plating, heat treatment was performed using a box annealing method or a continuous annealing method in an atmosphere of a reducing protective gas, and a heat diffusion alloying treatment of the plating layer was performed. Further, after the heat treatment, temper rolling was performed at a rolling rate of 1.2%. Samples (sample numbers 1 to 10) of the plated steel sheets for battery containers shown in Tables 2 and 3 were prepared as described above.

[Create battery container]
A blank was punched out from these samples Nos. 1 to 10 with a diameter of 57 mm, and a cylindrical LR6 type battery (AA size battery) having an outer diameter of 13.8 mm and a height of 49.3 mm was obtained by ten-stage drawing. Molded into a container.

[Create battery]
Using this plated steel sheet for battery containers, an alkaline manganese battery was prepared as follows. Manganese dioxide and graphite were collected at a ratio of 10: 1, and potassium hydroxide (10 mol) was added and mixed to prepare a positive electrode mixture. Next, this positive electrode mixture was pressed in a mold to form a donut-shaped positive electrode mixture beret having a predetermined size. Next, a conductive material mainly composed of graphite powder was applied to the inner surface of the battery container. The positive electrode mixture beret previously produced was press-inserted into the battery container. Next, the negative electrode plate spot-welded with the negative electrode current collector rod was attached to the battery container. Next, a separator made of vinylon woven fabric is inserted along the inner periphery of the positive electrode mixture beret pressure-inserted into the battery container, and a negative electrode gel made of potassium hydroxide saturated with zinc particles and zinc oxide is inserted into the battery container. Filled in. Further, an insulating gasket was attached to the negative electrode plate and inserted into the battery container, followed by caulking to prepare an alkaline manganese battery.

[Characteristic evaluation]
The characteristics of the batteries prepared using the battery containers prepared from the samples Nos. 1 to 10 as described above were evaluated as follows.

<Short-circuit current>
After leaving the battery at 80 ° C. for 3 days, an ammeter was connected to the battery, a closed circuit was provided, and the current value was measured, which was defined as a short-circuit current. It shows that a characteristic is so favorable that a short circuit current is large.

<Discharge characteristics>
After leaving the battery at 80 ° C. for 3 days, the produced battery was discharged to a constant current of 1.5 A, and the time until the final voltage of 0.9 V was reached was measured as the discharge time. The longer the discharge time, the better the discharge characteristics.

<Intermittent discharge characteristics>
As an evaluation of the double-added inter-single discharge, an operation of discharging for 2 seconds at 2A and then discharging for 29.5 seconds at 0.25A is one cycle, and intermittent discharge is repeated until the voltage reaches 1.0V throughout. The number of cycles was measured. The larger the number of cycles, the better the intercussion discharge characteristics. These evaluation results are shown in Table 4.

<Leakage evaluation>
After the battery was prepared, it was inserted into a constant temperature and humidity atmosphere of 90 ° C. and RH 60%, and the leakage rate (%) of the electrolyte solution after lapse of 5, 10, 15, 20 days was determined. These evaluation results are shown in Table 4.

    As shown in Table 4, the plated steel sheet for battery containers according to the present invention is obtained by applying nickel-titanium alloy plating to the inner side of the battery container, followed by tin plating, followed by heat treatment. In addition, the short-circuit current, the discharge characteristics, and the intermittent discharge characteristics are equivalent to or equal to or better than those heat-treated after nickel plating. Regarding leakage resistance, the steel plate for the battery container according to the present invention is not suitable after the nickel plating according to the conventional method, followed by the tin plating and then the heat treatment. Good leakage resistance equivalent to that of the heat-treated product. That is, the plated steel sheet for battery containers of the present invention is equivalent to the plated steel sheet for battery containers having the same or better battery characteristics than the plated steel sheet for battery containers, which is superior in battery characteristics by the conventional method, and excellent in leakage resistance by the conventional method. It has the resistance to leakage.

  The plated steel sheet for battery containers according to the present invention is formed by applying nickel-titanium alloy plating to the inner side of the battery container, followed by tin plating, and then heat-treating the plated layer to form a heat diffusion alloy. A metal layer containing titanium, nickel, and tin is formed on the surface. By forming this metal layer, microcracks are generated when the battery container is molded, and adhesion with the positive electrode mixture is improved and excellent discharge characteristics are obtained. Further, since titanium is contained in the metal layer, gas generation due to dissolution of iron is suppressed by a sacrificial dissolution action of titanium with respect to iron, so that leakage resistance is also improved. As a result, it is possible to provide a plated steel sheet for battery containers with improved discharge performance without deteriorating leakage resistance.

It is a schematic sectional drawing which shows an example of the plated steel plate for battery containers of this invention. It is a schematic sectional drawing which shows another example of the plated steel plate for battery containers of this invention. It is a schematic sectional drawing which shows another example of the plated steel plate for battery containers of this invention. It is a schematic sectional drawing which shows another example of the plated steel plate for battery containers of this invention. It is a schematic sectional drawing which shows another example of the plated steel plate for battery containers of this invention. It is a schematic sectional drawing which shows another example of the plated steel plate for battery containers of this invention.

Claims (11)

A plated steel sheet for battery containers, wherein a metal layer containing titanium, nickel, and tin is formed on a steel sheet on the side that is to be the battery container inner surface of the steel sheet. 2. The plated steel sheet for battery containers according to claim 1, wherein an iron-nickel-titanium alloy layer and a nickel-titanium-tin alloy layer are formed in order from the steel sheet side of the steel sheet which is the inner surface of the battery container. . 2. The battery container according to claim 1, wherein an iron-nickel-titanium alloy layer and an iron-nickel-titanium-tin alloy layer are formed in order from the steel sheet side of the steel sheet that is the inner surface of the battery container. Plated steel sheet. The iron-nickel-titanium alloy layer, the nickel-titanium alloy layer, and the nickel-titanium-tin alloy layer are formed in order from the steel plate side on the side that becomes the battery container inner surface of the steel plate. Plated steel sheet for battery containers. 2. The battery container plating according to claim 1, wherein an iron-nickel alloy layer, a nickel layer, and a nickel-titanium-tin alloy layer are formed in order from the steel sheet side of the steel sheet that is the inner surface of the battery container. steel sheet. The plated steel sheet for battery containers according to claim 1, wherein an iron-nickel alloy layer and a nickel-titanium-tin alloy layer are formed in order from the steel sheet side of the steel sheet that is the inner surface of the battery container. An iron-nickel alloy layer, an iron-nickel-titanium alloy layer, a nickel-titanium alloy layer, and a nickel-titanium-tin alloy layer are formed in this order from the steel plate side on the side that becomes the battery container inner surface of the steel plate. The plated steel sheet for battery containers according to claim 1. The battery container formed by shape | molding the plated steel plate for battery containers in any one of Claims 1-7 in a bottomed cylindrical shape. A battery comprising the battery container according to claim 8. A method for producing a plated steel sheet for a battery container, comprising applying nickel-titanium alloy plating to at least a side of the steel sheet that is to be the inner surface of the battery container, and subsequently applying tin plating to the upper layer, followed by heat treatment. A battery container characterized in that nickel plating is applied to at least the battery container inner surface side of the steel sheet, then nickel-titanium alloy plating is applied to the upper layer, and then tin plating is applied to the upper layer, followed by heat treatment. Method for producing plated steel sheets.

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