JP2000011966A - Battery can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery can which has good high temperature storage and long time elapsed resistance due to changes over a long time, and has favorable discharge characteristic by specifying the thickness of an Sn-contained alloy containing Ni or Ni and Fe of the inner surface of a can. SOLUTION: Sn content is 0.05-1.2 g/m2, preferably 0.05-0.5 g/m2, and the thickness of a Sn-contained alloy layer is set 0.02-0.45 μm. The Sn concentration of the can inner surface is substantially at a gradient toward the low concentration side from the surface of the alloy layer toward the inside, and preferably it has a two-layer structure including an outer layer of Sn-Ni alloy layer and an inner layer of Sn-Ni-Fe alloy layer. Ni-plating is applied to one surface of a steel plate, Sn-plating is applied thereon, and heat treatment is conducted to diffuse Sn in Ni, thereby using a steel plate where Sn-contained alloy layer is formed. The inside surface of the steel plate 1 of the battery can wall has Ni-Sn alloy layer 4 and Sn-Ni-Fe alloy layer 5 formed inside. An Ni-Fe alloy layer 6, where Ni is diffused in a steel plate is formed, and the outermost layer is an Ni-Co alloy layer 7 having gloss.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery can containing a power generating element using an alkaline electrolyte such as an alkaline manganese battery, a nickel-cadmium battery, and a lithium battery.

[0002]

2. Description of the Related Art A nickel-plated steel plate is generally used as a battery can for an alkaline electrolyte, and a cylindrical battery can is formed from the steel plate as described in JP-B-7-99686. Transfer blanking, in which a blank made of nickel-plated steel sheet punched into a die is transferred to a plurality of dies having different drawing diameters and formed by drawing in a cylindrical shape, and a plurality of ironing diameters arranged in multiple stages on the coaxial line are different. DI formed by pressing and pressing with a punch continuously through a die and drawing and ironing into a cylinder
(Draw and ironing) A drawing method is used. In a battery using an alkaline electrolyte represented by an alkaline manganese battery, a battery can having nickel plating or a layer obtained by heat-treating the nickel plating is used as an inner alloy layer of the battery. This battery can, that is, a can whose surface in contact with the alkaline electrolyte is Ni or a Ni-Fe alloy, has a drawback that the operating voltage decreases with time. There is also a disadvantage that the effective capacity of the battery at the time of discharging is reduced. In order to solve this drawback, a method (Japanese Patent Publication No. 7-70320) using a Ni—Co alloy layer instead of Ni plating on the inner surface of the can is proposed. However, this method has the drawback that the Ni-Co alloy has poor formability, the Ni-Co alloy layer cracks during the forming of the original sheet into a can, and the underlying steel is exposed, so that red rust occurs during storage and the corrosion resistance is poor. there were. Further, cobalt is expensive and is not economically preferable.

Also, a method of alloying Sn with Ni for the purpose of reducing the internal resistance of the nickel layer on the inner surface of the can in contact with the positive electrode mixture (JP-A-7-300695, WO95 / 115)
27, JP-A-7-122246) has been proposed. These are economically preferable because tin is relatively inexpensive.The internal contact resistance with the positive electrode mixture is reduced and the operating voltage is secured, but the discharge capacity decreases during high-temperature storage or long-term storage, and the equipment operates. However, there is a disadvantage that the effective amount of electricity decreases. According to the research of the present inventors, it has been found that this defect occurs when the Sn content and thickness are large. In order to improve the adhesion to the positive electrode mixture and reduce the contact resistance, it is preferable that the inner surface of the can wall of the battery can have rough skin, small cracks and irregularities, In order to cause roughening of the surface of the steel plate, the hardness of the plating layers on both sides of the steel plate is made different, and when the battery can is formed, a plating layer having a high hardness is used on the inner surface of the battery can, and a plating layer having a lower hardness is used on the outer surface of the battery can. No. 306439. However, since this battery can caused rough skin on the inner surface of the can, rust is likely to occur due to exposure of the steel surface due to rough skin, and alloy elements used to harden the plating layer for the purpose of generating rough skin There is a disadvantage that the discharge performance of the battery is deteriorated. Also, if the surface of the steel plate of the battery can becomes rough, the corrosion resistance deteriorates and rust occurs. Therefore, the crystal grain size of the steel plate is reduced to 10 or more, and the grain structure is made fine. After forming the crystal grains X ', even if the crystal X' is compressed by drawing, no remarkable irregularities are generated on the surface and the plating layer on the surface can be followed, so that the surface gloss is good and the corrosion resistance is good. Has been proposed in Japanese Patent Application Laid-Open No. 9-30643. However, this battery can has the drawback that the strength of the steel plate is increased due to the small crystal grains, the forming load when forming the cylindrical can from the steel plate is increased, and the forming becomes difficult. Japanese Unexamined Patent Publication No. Hei 7-300695 discloses Sn for imparting scratch resistance to a Ni plating layer.
-A battery can provided with a Ni plating layer has been proposed. However, this battery can has a thickness of Sn-Ni alloy layer or Sn-N
No description is given of the Sn content in the i-alloy layer.

[0004]

The above-mentioned discharge characteristics are important for a battery can. Typical discharge characteristics include operating voltage and discharge capacity. The operating voltage is the voltage that is applied to the device when the device is electrically connected to the device, which is electrically represented by a resistor. Different fixed or higher voltages are required. The operating voltage corresponds to the voltage across the resistor when a certain resistor is connected in series. Although this resistance varies depending on the type of equipment used, it is equivalent to a resistance of about 2.5Ω in MD players, portable liquid crystal televisions, and the like that have been widely used in recent years. The operating voltage decreases as the internal resistance of the battery increases. The internal resistance of the battery is the internal resistance of the battery obtained by integrating the contact resistance at the interface between the battery can and the positive electrode material and the resistance generated by the consumption of the battery electrode material (the consumption of the positive electrode material and the negative electrode material). In the measurement, a constant resistance is connected and the measurement is performed over time. In general, the higher the operating voltage after a certain period of time, the more stable the device can operate,
It is preferable in terms of battery performance.

[0005] Another characteristic is a capacity that can be discharged before a device stops operating normally, that is, a "discharge capacity". The discharge capacity is the value of the amount of electricity that flows when the voltage across the resistor when a certain resistor is connected in series up to 0.9 V, which is the end point of the service life of the battery. Batteries basically have the property of self-consumption during storage. The self-consumption is a phenomenon in which the battery capacity is reduced when the battery is stored without using the battery connected to the device. There are various reasons for self-depletion, but one of the major reasons is that one container contains a positive electrode material and a negative electrode material, and both are separated by a separator, but they are connected by an electrolytic solution. Therefore, during storage, the chemical substances of the positive electrode and the negative electrode gradually react and are consumed. The degree of self-depletion is large when stored at high temperatures or when stored for a long time. Recently, it has been required to have good discharge characteristics even after high-temperature storage or long-term storage. The present inventors have studied such a problem, and have clarified that the battery container also influences this self-consumption. Even when stored at a high temperature or stored for a long period of time, a battery that has a high operating voltage and can maintain a high discharge capacity is made of Ni contained in the Sn-containing alloy layer containing Ni or Ni and Fe provided on the inner surface of the battery can. The present invention was completed by elucidating what can be obtained by setting the amount and the thickness of the Sn-containing alloy layer in a special range, and clarifying that the above-mentioned problems can be solved.

[0006]

Means for Solving the Problems The present invention provides: "1. The inner surface of the can has a Sn content of 0.05 to 1.2 g / m2.
^2. A battery can excellent in high-temperature storage and long-term aging resistance, characterized in that it is Ni or Ni-containing alloy containing Ni and Fe, and the thickness of the Sn-containing alloy layer is 0.02 to 0.45 μm. 2. The Sn content of the Sn-containing alloy layer on the inner surface of the can is 0.05
The battery can according to item 1, which has a weight of from 0.5 g / m ² to 0.5 g / m ² . 3. The Sn concentration of the Sn-containing alloy layer on the inner surface of the can is substantially inclined inward from the surface of the alloy layer toward the lower concentration side,
Item 3. The battery can described in Item 1 or 2. 4. In the Sn-containing alloy layer on the inner surface of the can, the outer layer is Sn-
A Ni alloy layer, and the inner layer is a Sn—Ni—Fe alloy layer 2
Item 4. The battery can according to Item 3, which has a layer structure. About.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the inner surface of a battery can is a Sn-containing alloy layer containing Ni or Ni and Fe, and the Sn content of the Sn-containing alloy layer is 0.05 to 0.5 g / m2.
Must be ² . As a partner element of the Sn alloy, it is necessary that Ni or Fe is mainly used.
The reason is that one or both of the two elements and Sn
Is to have good corrosion resistance to the highly alkaline solution as an electrolyte within the above range. Also F
e is a main element of steel, and steel is widely used to maintain container strength. Mana Ni is a plating element that has been widely used as a battery can material for high alkaline electrolytes. If the Sn content is less than 0.05 g / m ² , the nickel surface undergoes a chemical reaction with the alkaline electrolyte over time, forming a chemically inert passive film on the surface. Since this film is inferior in electric conductivity, when the battery is discharged, the electric resistance increases and the operating voltage decreases, which is not preferable. Since the operating voltage is reduced, the time required to maintain the operating voltage required for normal operation of the device is shortened, and the effective capacity of the battery is substantially reduced, which is not preferable as the discharge capacity characteristics of the battery.

If the Sn content exceeds 1.2 g / m ² , the amount of Sn dissolved from the alloy layer into the electrolytic solution increases, and a positive electrode agent such as MnO ₂ is reduced by the Sn dissolution reaction. As a result, the battery capacity decreases, which is not preferable. This phenomenon is particularly remarkable when stored at high temperatures or when stored for a long time. The Sn content of the inner surface of the can is within this range, and a particularly preferable range in which the operating voltage is high and the battery capacity does not decrease is the Sn content of 0.05 to 0.5 g / m ² .
The Sn content of the Sn-containing alloy layer on the inner surface of the can was 0.05%.
Even if it is 1.2 g / m ² , the thickness of the Sn-containing alloy layer must be 0.02 to 0.45 μm. If the thickness of the Sn-containing alloy layer is less than 0.02 μm, the S
The concentration of n is too large, the dissolution rate of Sn is high, and the battery capacity decreases rapidly with time.
If it exceeds m, the surface Sn concentration is small and the operating voltage decreases with time, which is not preferable. Further, the Sn-containing alloy layer on the inner surface of the can may be only the Sn-Ni layer, or a single Ni layer may be provided below the Sn-containing alloy layer. Sn-containing alloy layer is Sn-N
In the case of two layers, i-alloy layer and Sn-Ni-Fe alloy layer, there is no single Ni layer and the alloy layer structure is relatively uniform, so that the alloy layer is relatively uniform and the alloy layer has defects. Difficult and preferred.

In the present invention, a steel sheet is used in which at least one surface of the steel sheet is Ni-plated, Sn plating is applied thereon, and then heat treatment is performed to diffuse Sn into the Ni layer to form a Sn-containing alloy layer. . At this time, in order for Sn to completely diffuse into Ni and form an alloy, the amount of Ni plating needs to be about 1.5 times or more the amount of Sn plating. The steel sheet for a battery used in the present invention is generally a steel sheet used for a can material,
Ni plating in an i-plating bath, and S
Sn plating in n plating bath, 5 to 15 at 450 to 650 ° C
It can be obtained by heating for a time. That is, the steel plate is a low-carbon steel having 0.005 to 0.15% carbon and a temper of T1 to T5 and DR6 to D6.
R9 material or the like is used. As the annealing method, a continuous annealing method or a batch annealing method can be used. As the Ni plating bath, a Watt bath, a sulfamic acid bath, and a chloride bath can be used. For Sn plating, a ferrostan bath, a halogen bath, an alkaline bath, or the like can be used. The Sn-containing alloy layer on the inner surface side of the can of this steel sheet has a Sn content in the Sn alloy layer of 0.05 to 1.2 g / m ² , and Sn is substantially inward from the surface of the alloy layer. The Sn-containing alloy layer has a thickness of 0.02 to 0.9 μm. At this time, the Sn-containing alloy layer may be only the Sn-Ni layer, or may be a single Ni layer below the Sn-Ni alloy layer. Sn-Ni alloy layer having a thickness of 0.9 μm or less and Sn-Ni having a thickness of 0.9 μm or less
In the case of two layers of -Fe alloy layer, since there is no single Ni layer and the structure of the alloy layer is relatively uniform, relatively uniform forming is achieved and defects of the alloy layer hardly occur, which is preferable.
In addition, the heat diffusion treatment after plating causes the Ni layer between the steel sheet and the Ni layer.
The provision of an alloy layer of -Fe is made of steel and a Ni layer or S
It is preferable because the adhesion with the alloy layer containing n-Ni is improved. However, from the viewpoint of further stabilizing the adhesion, it is preferable that the thickness of the Ni-Fe alloy layer be 0.5 to 5.0 µm.

This steel sheet is formed with the Sn-containing alloy layer side as an inner surface to form a cylindrical battery can. The forming method at this time is not particularly limited, but it is possible to apply drawing, drawing and ironing, ironing, drawing and drawing, or a combination thereof. The battery can is formed by molding an original plate, and the side wall of the can can be made thinner than the original plate thickness by a molding method. In this case, the reduction rate represented by the following equation is different. Reduction rate = ((plate thickness of original plate−plate thickness of can side wall) × 10
0) / Thickness of original plate This reduction rate is 0% in a simple drawing process, and can be up to about 50% in a stretch drawing process or a drawing and ironing process. The plate thickness and plating thickness of the original plate become thinner in proportion to this reduction rate. In order to make the thickness of the alloy layer on the side wall of the can body in an appropriate range, it is necessary to set the thickness of the alloy layer of the original plate in accordance with the reduction. When the Sn-containing alloy layer on the inner surface side of the can is in the above range, the Sn-containing alloy layer undergoes slip deformation in forming the original sheet into the can, so that the Sn-containing alloy layer does not crack and the steel surface is exposed. Therefore, even when stored at a high temperature or for a long period of time, it has good corrosion resistance against red rust and the like, which is preferable. Further, the battery can of the present invention can be applied to all battery cans using an alkaline electrolyte. The size is LR6, LR20, LR14,
It can be used in LR1, LR44 and the like. However, the size is not limited.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a battery can wall of the present invention. 1 is a steel plate of the can wall of the battery can, and 4 on the inner surface side is Ni-Sn.
It is an alloy layer. 5 is Sn—Ni formed inside from 4
A Fe alloy layer, in which a Ni layer plated on the surface of the steel sheet and Sn plated thereon diffused into the steel sheet to form an alloy with iron. At this time, S
There is no problem if there is no n-Ni-Fe alloy layer but a single Ni layer. Reference numeral 6 denotes a layer in which Ni plated in contact with the steel sheet diffuses into the steel sheet to form an alloy with iron. Reference numeral 3 denotes the outer surface side of the steel sheet, and it is not always necessary to form the same plating layer as the inner surface side, but in this example, the same plating layer as the inner surface side is formed. The outermost layer 7 is a Ni—Co alloy plating layer having a gloss. 7, the thickness of the Ni—Co alloy layer is 0.5 μm or more.
6.0 μm, and 4 Ni—Sn alloy layers and 5 Sn—
The combined thickness of the Ni—Fe alloy layers is 0.02 μm to 0.4
5 μm, and the thickness of the Ni—Fe alloy layer 6 is 0.5 μm.
~ 5.0μ.

FIG. 2 shows plated raw materials for producing the battery can of the present invention. 9 is a Ni layer plated on the surface of the steel sheet 1. Reference numeral 8 denotes a Sn layer plated on a Ni layer. The same plating layer is provided on the inner surface 2 and the outer surface 3. This Sn
When a steel sheet plated with Ni and Ni is subjected to thermal diffusion treatment, Ni-Sn
An alloy plated steel sheet is obtained. When a bright Ni—Co alloy plating is performed on the outer surface side of the Ni—Sn alloy layer steel sheet, a steel sheet having a gloss layer is obtained.

Next, an example of a method for manufacturing a battery can according to the present invention will be described with reference to FIGS. FIG. 3 shows Ni-S of the present invention.
4 shows a cup obtained by drawing a steel plate provided with an n-alloy layer. 0 is the thickness _{t 0} in the case of using the material of the initial thickness 0.25mm.
25 mm. Figures 4 and 5 show cans that have been drawn sequentially. It can be seen that the diameter of the cup is reduced and the depth is increased.
FIG. 6 shows a can which has been ironed and re-drawn, the sidewall thickness is t ₀ =
If it is 0.25 mm, the thickness will be a little thin, for example, t ₂ = 0.22 mm. The redrawing step is not limited to three times.
In FIG. 6, the flange portion is left, but it may be narrowed down entirely. 7, leaving the opening of the can of FIG. 6, the diameter d _2,
Shows a state obtained by molding a small-diameter cylindrical portion of the thickness t _1, is formed by re-drawing and ironing. When t ₂ = 0.22 mm, for example, the thickness becomes thinner at t ₁ = 0.16 mm. FIG. 8 shows a state in which the pip portion is formed, but may be omitted if no pip is required. FIG. 9 shows that the diameter d ₃ and the thickness t ₃ are obtained by ironing and re-drawing the opening end side of the portion left in FIG.
Is formed, and an intermediate tapered cylindrical portion has a thickness t _2.
Is maintained. In this example _{t 3} is 0.20mm.
FIG. 10 shows the trimmed state. Thereafter, although not shown, cleaning is performed to remove the molding lubricant.

FIG. 11 is an intensity curve with respect to the sputtering time of each element on the inner surface of the can. Fe start point, Sn end point,
The end point of Ni is shown. FIG. 12 is a discharge curve of the battery. It can be seen that the operating voltage decreases due to the discharge. FIG. 13 is a bar graph showing the operating voltage. In each of the examples, the operating voltage is high, but in the comparative examples, most are low. FIG. 14 is a bar graph showing the amount of discharge electricity. Each of the examples has a large amount of discharge electricity, but the comparative example has a small amount.

[0015]

EXAMPLE 1 A low carbon steel sheet having a thickness of 0.25 mm, temper T1, and BA annealing was used, and both surfaces were subjected to electrolytic plating using a Watt bath at 8.9.
forming a Ni plating layer of g / ^{m 2,} the upper forming an Sn plating layer of 1.5 g / ^{m 2} on both surfaces in electroplating with Ferrostan bath was the batch heat treatment for 6 hours at 500 ° C..
This plated steel sheet is blanked to a blank diameter of 53 mm, drawn into a cup, stretched and drawn again three times, and ironed into the cup.
Finally, cup outer diameter is 13.8mm and side wall thickness is 0.20
mm cups. At this time, the side walls have a reduction of 20%. A pip portion is formed in this cup, and the opening end side is ironed to form a large-diameter cylindrical portion by re-drawing.
It was trimmed to 0 mm, and then washed and dried to prepare a can for an LR6 battery. The Sn content of the Sn alloy layer on the inner surface of the side wall of this can was 1.2 g / m ² , and the Ni content was 7 g / m ^2.
And the Sn—Ni alloy layer thickness is 0.34 μm,
The thickness of the Sn—Ni—Fe alloy layer is 0.11 μm,
The thickness of the i-Fe alloy layer was 1.2 μm. Sn and N
For the measurement of i content, the side wall of the can was cut out, the inner surface was covered with a tape, the outer plating layer was dissolved with acid, then the inner tape was peeled off, the test piece was cut into a fixed area test piece, and the inner plating layer was completely dissolved in acid. The amount of Sn and the amount of Ni were measured by atomic absorption spectroscopy, and the content of each metal was calculated. The measurement of the thickness of the Sn—Ni alloy layer, the thickness of the Sn—Ni—Fe alloy layer, and the thickness of the Ni—Fe alloy layer is performed by glow discharge spectroscopy (hereinafter abbreviated as GDS) from the inner surface of the can side. Was measured in the depth direction from the sample, and the thickness of each alloy layer was determined. FIG. 11 shows an intensity curve of each element with respect to the sputtering time. The thickness of the alloy layer was measured as indicated by the arrow in the figure. At this time, the thickness of each alloy layer was determined at the intersection of the contact points on the strength curve of each element. That is, the thickness of the Sn-Ni alloy layer is the thickness from the surface to the lower layer of Fe,
-The thickness of the Fe alloy layer is the thickness from where Fe appears to where Sn disappears, and the thickness of the Ni-Fe alloy layer is the thickness from where Sn disappears to where Ni disappears. The thickness of the Sn-containing alloy layer refers to the thickness from the surface to the point where Sn disappears. In the case where the Sn—Ni—Fe alloy layer does not exist but is not the present embodiment, the thickness of the Sn—Ni alloy layer is the thickness from the surface to the point where Sn disappears.
The thickness of the e-alloy layer is a thickness from a point where Fe appears to a point where Ni disappears. The sputtering speed was determined using a Ni-plated steel plate having a known plating thickness. As a result of the measurement, the Sn—Ni alloy layer was 0.3
4 μm, the thickness of the Sn—Ni—Fe alloy layer was 0.11 μm, and the total thickness of the Sn alloy layer was 0.45 μm. The entire inner surface of the can is spray-coated with a vinyl chloride resin containing graphite powder and baked by a usual method, and the graphite content is 50%.
Was formed. This can was filled with a battery material by a general method to prepare a battery. That is, MnO ₂ powder, graphite powder, and KOH solution are mixed and pressurized, and a positive electrode material formed into a cylindrical pellet is inserted, can bead molding is performed, a separator is inserted, and an 8M concentration KOH electrolyte is injected. A powdered negative electrode gel was injected, a sealant was applied, and then the negative electrode cap was crimped to prepare a battery. L created in this way
After storing the battery of R6 at 70 ° C. for 3 weeks, the battery performance was measured. This aging is equivalent to about four years or more at room temperature. For the measurement, a 2.5Ω resistor was connected in series with the battery, and the voltage across the resistor was measured over time. Further, a coulomb meter was connected in series to this circuit, and the amount of discharged electricity was measured. The discharge curve in this measurement is as shown in FIG. 12, and as an evaluation of the characteristics, the operating voltage after 30 minutes and the electric current which flowed until the voltage decreased from the initial voltage of about 1.4 V to 0.9 V were evaluated. The amount was used. The former is an index of the internal resistance of the battery, and the larger is the higher the performance. The latter is generally a threshold voltage at which the device can operate normally.
It is an index of the effective battery capacity up to 9V. These measurement results are shown in Table 1 and FIGS. After 30 minutes, the operating voltage and the amount of discharged electricity up to 0.9 V were all good.

[0016]

[Table 1]

Example 2 The amount of Sn plating on a steel sheet was set to 0.6 g / m ² ,
Except that the content was set to 0.5 g / m ² , the same procedure as in Example 1 was performed to produce a plated steel sheet, make a can, apply graphite resin, fill, and evaluate. These results are shown in Table 1 and FIGS. The operating voltage after 30 minutes and the amount of discharge electricity up to 0.9 V were all good.

Example 3 The amount of Sn plating on a steel sheet was set to 0.06 g / m ² ,
except that the n content 0.05 g / m ² in the same manner as in Example 1, plated steel sheet production, can-making, graphite resin coating, filling, the evaluation was performed. These results are shown in Table 1 and FIGS.
It is shown in FIG. The operating voltage after 30 minutes and the amount of discharge electricity up to 0.9 V were all good.

Comparative Example 1 The amount of Sn plating on a steel sheet was set to 1.9 g / m ² , and the
Except for changing the content to 1.59 / m ² , the same procedure as in Example 1 was performed to produce a plated steel sheet, make a can, apply graphite resin, fill, and evaluate. These results are shown in Table 1 and FIGS. It can be seen that the operating voltage after 30 minutes is good, but the amount of discharged electricity up to 0.9 V is considerably small and the amount of discharged electricity is reduced.

Comparative Example 2 The amount of Sn plating on a steel sheet was set to 0.04 g / m2,
Except that the n content was 0.03 g / m ² , the production of a plated steel sheet, can making, graphite resin application, filling, and evaluation were performed in the same manner as in Example 1. These results are shown in Table 1 and FIGS.
It is shown in FIG. It can be seen that the operating voltage after 30 minutes is low, and the amount of discharged electricity up to 0.9 V is slightly smaller.

Comparative Example 3 The amount of Ni plating on a steel sheet was 17.5 g / m ² , and no heat treatment was performed after plating without Sn plating.
Except that the n content was 0 g / m ² , the Ni content was 14 g / m ² , and the Ni—Fe alloy layer was 0 μm, the same procedure as in Example 1 was carried out to manufacture a plated steel sheet, make a can, apply graphite resin,
Filling and evaluation were performed. These results are shown in Table 1 and FIGS. It can be seen that the operating voltage after 30 minutes is low, and the amount of discharge electricity up to 0.9 V is slightly small.

Comparative Example 4 The amount of Ni plating on a steel sheet was set to 17.5 g / m ² , the Sn plating was not performed, the Sn content on the can side was set to 0 g / m ² , and the can side N
In the same manner as in Example 1 except that the i content was set to 14 g / m ² , production of a plated steel sheet, can making, application of graphite resin, filling,
An evaluation was performed. These results are shown in Table 1 and FIGS. It can be seen that the operating voltage after 30 minutes is low, and the amount of discharged electricity up to 0.9 V is slightly small.

Comparative Example 5 When heat-treating a steel sheet after plating, the heat-treating condition was 500 ° C.
To 12 hours, and the can side wall Sn content 1.2 g / ^{m 2,}
Except that the thickness of the Sn-containing alloy layer was increased, in the same manner as in Example 1, production of a plated steel sheet, can making, application of graphite resin, filling,
An evaluation was performed. These results are shown in Table 1 and FIGS. It can be seen that the operating voltage after 30 minutes is low, and the amount of discharged electricity up to 0.9 V is slightly small.

[0024]

The present invention is excellent in high-temperature storage property and long-term storage property, and has an excellent effect of having good discharge characteristics even after such storage.

[Brief description of the drawings]

FIG. 1 is a sectional view of a can wall of a battery can of the present invention.

FIG. 2 is a sectional view of a plated steel sheet for manufacturing a battery can of the present invention before heat treatment.

FIG. 3 is an explanatory view of a manufacturing process of the battery can of the present invention.

FIG. 4 is an explanatory diagram of a manufacturing process of the battery can of the present invention.

FIG. 5 is an explanatory view of a manufacturing process of the battery can of the present invention.

FIG. 6 is an explanatory view of a manufacturing process of the battery can of the present invention.

FIG. 7 is an explanatory diagram of a manufacturing process of the battery can of the present invention.

FIG. 8 is an explanatory diagram of a manufacturing process of the battery can of the present invention.

FIG. 9 is an explanatory diagram of a manufacturing process of the battery can of the present invention.

FIG. 10 is an explanatory view of a manufacturing process of the battery can of the present invention.

FIG. 11 is an intensity curve with respect to a sputtering time of each element of a can wall.

FIG. 12 is a discharge curve of a battery.

FIG. 13 is a graph showing an operating voltage.

FIG. 14 is a graph showing the amount of discharge electricity.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel wall of can wall of battery can 2 Inner side 3 Outer side 4 Sn-Ni alloy layer 5 Sn-Ni-Fe alloy layer 6 Ni-Fe alloy layer 7 Ni-Co alloy layer 8 Sn layer 9 Ni layer

Claims (4)

[Claims] 1. The inner surface of a can has a Sn content of 0.05 to 1.2.
g / m ² , or a Sn-containing alloy containing Ni and Fe, wherein the thickness of the Sn-containing alloy layer is 0.02 to 0.45.
A battery can excellent in high-temperature storage and long-term aging resistance characterized by having a thickness of μm. 2. The battery can according to claim 1, wherein the Sn content of the Sn-containing alloy layer on the inner surface of the can is 0.05 to 0.5 g / m ² . 3. The battery can according to claim 1, wherein the Sn concentration of the Sn-containing alloy layer on the inner surface of the can is substantially inclined inward from the surface of the alloy layer toward the lower concentration side. 4. The battery can according to claim 3, wherein in the Sn-containing alloy layer on the inner surface of the can, the outer layer is a Sn—Ni alloy layer, and the inner layer has a two-layer structure of a Sn—Ni—Fe alloy layer.