Surface-treated metal sheet for battery

Abstract

Provided is a surface-treated metal sheet for a battery, comprising an iron-based metal substrate and a tin layer that is provided on at least one side of the metal substrate, wherein the crystal orientation index Sn(200) of the (200) plane of the tin layer is less than 3.50 and the ratio (Sn(200) / Fe(200)) of the crystal orientation index Sn(200) to the crystal orientation index Fe(200) of the (200) plane of the metal substrate is not more than 1.00.

Description

Surface-treated metal sheets for batteries

[0001] The present invention relates to a surface-treated metal sheet for batteries that has an excellent effect of suppressing gas generation.

[0002] Nickel-cadmium batteries, nickel-metal hydride batteries, etc. are widely known as secondary batteries, so-called alkaline batteries, whose electrolyte is an alkaline aqueous solution. Among alkaline secondary batteries, air batteries and nickel-zinc batteries, which use nickel hydroxide or the like for the positive electrode, zinc or the like for the negative electrode active material, and an alkaline aqueous solution for the electrolyte, are being actively developed as next-generation batteries.

[0003] The advantages of nickel-zinc batteries include a high electromotive force and a high energy density for an aqueous battery, the low cost of zinc, the small amount of rare metals used, the fact that both nickel and zinc are recyclable metals, and the use of an aqueous electrolyte, which makes them safer than lithium-ion batteries.

[0004] On the other hand, one of the challenges in practical application of zinc-air batteries and nickel-zinc batteries as secondary batteries is the problem of hydrogen gas generation (hereinafter also referred to as gas generation) during charging and discharging (including natural discharge). If hydrogen gas generation occurs and the amount generated becomes too large, it can cause a decrease in battery performance, an increase in internal pressure, and lead to battery leakage. These problems can occur particularly noticeably in batteries in which zinc is involved in the battery reaction.

[0005] It has been known that the above-mentioned problem of hydrogen gas generation can be solved by applying a material with a high hydrogen overvoltage to the negative electrode current collector. For example, Patent Document 1 discloses a nickel-zinc battery in which the negative electrode current collector is made of a tin-plated metal material with a high hydrogen overvoltage.

[0006] Japanese Patent Application Laid-Open No. 2019-139986

[0007] However, as described in Patent Document 1, when the concentration of potassium hydroxide in the electrolyte is set to a high concentration of 20% by weight or more in order for the alkaline secondary battery to exhibit sufficient battery performance, the technology described in Patent Document 1 has the problem that, depending on the state of the tin plating, gas generation may not be sufficiently prevented.

[0008] An object of the present invention is to provide a surface-treated metal sheet for batteries that is excellent in suppressing gas generation during charging and discharging of alkaline secondary batteries in an environment of a high-concentration electrolyte as described above.

[0009] As a result of intensive research into achieving the above-mentioned object, the inventors have found that the above-mentioned object can be achieved by a surface-treated metal sheet for batteries, which comprises a metal substrate and a tin layer provided on at least one surface of the metal substrate, and in which the crystal orientation indexes of the metal substrate and the tin layer are controlled, and have thus completed the present invention.

[0010] [1] A first aspect of the present invention is a surface-treated metal sheet for batteries, comprising an iron-based metal substrate and a tin layer provided on at least one of the metal substrates, wherein the tin layer has a crystal orientation index Sn(200) of a (200) plane of less than 3.50, and the ratio of the crystal orientation index Sn(200) to the crystal orientation index Fe(200) of the (200) plane of the metal substrate (Sn(200) / Fe(200)) is 1.00 or less.

[0011] [2] A second aspect of the present invention is the surface-treated metal sheet for a battery according to the first aspect, wherein the crystal orientation index Fe(200) is 2.55 or more.

[0012] [3] A third aspect of the present invention is the surface-treated metal sheet for a battery according to the second aspect, wherein the crystal orientation index Fe(200) and the crystal orientation index Sn(200) satisfy the following formula (1): Sn(200)≦−(1 / Fe(200)−2.4) / 2+3.4) (1)

[0013] [4] A fourth aspect of the present invention is the surface-treated metal sheet for a battery according to any one of the first to third aspects, in which the metal substrate is a steel plate.

[0014] [5] A fifth aspect of the present invention is the surface-treated metal sheet for a battery according to the fourth aspect, wherein the steel sheet is a low-carbon steel or an ultra-low-carbon steel.

[0015] [6] A sixth aspect of the present invention is the surface-treated metal sheet for a battery according to any one of the first to fifth aspects, wherein the crystal orientation index Sn is 3.30 or less.

[0016] [7] Aspect 7 of the present invention is a method for manufacturing a tin layer having a tin coating amount of 3.0 g / m ２ Above, 35.0g / m ２ The surface-treated metal sheet for a battery according to any one of Aspects 1 to 6 is as follows:

[0017] According to the present invention, it is possible to provide a surface-treated metal sheet for batteries that can suppress gas generation.

[0018] FIG. 1 is a cross-sectional view of a surface-treated metal sheet for batteries according to an embodiment of the present invention.

[0019] The surface-treated metal sheet for batteries according to this embodiment is a surface-treated metal sheet used in batteries, such as a current collector for a negative electrode or a battery container for housing a power generating element of a battery. Examples of batteries include, but are not limited to, aqueous batteries using alkaline electrolytes, such as nickel-cadmium batteries, nickel-metal hydride batteries, air-zinc batteries, and nickel-zinc batteries, as well as non-aqueous batteries such as lithium-ion batteries. The surface-treated metal sheet for batteries according to this embodiment is suitable for aqueous batteries, particularly aqueous batteries in which zinc is involved in the battery reaction (e.g., nickel-zinc batteries), as a current collector or battery container. The surface-treated metal sheet for batteries according to this embodiment can be used in both primary and secondary aqueous batteries. The surface-treated metal sheet for batteries according to this embodiment is particularly suitable for alkaline secondary batteries, which are used in high-concentration electrolyte environments (e.g., electrolytes containing 20% ​​or more potassium hydroxide by weight).

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] 1 is a cross-sectional view of a surface-treated metal sheet for batteries 10 according to an embodiment of the present invention. As shown in FIG. 1, the surface-treated metal sheet for batteries 10 according to this embodiment includes a metal substrate 20 and tin layers 30 provided on both sides of the metal substrate 20.

[0022] While FIG. 1 illustrates an example in which a tin layer 30 is formed on both sides of the metal substrate 20, the configuration of the surface-treated metal sheet 10 for batteries is not particularly limited thereto. In the surface-treated metal sheet 10 for batteries, the tin layer 30 may be formed on at least one side of the metal substrate 20. Furthermore, in the present embodiment, the tin layer 30 may be formed on a surface where gas generation suppression is required. For example, when the surface-treated metal sheet 10 for batteries according to this embodiment is used as a negative electrode current collector (for example, when used as a negative electrode current collector for a nickel-zinc battery), a lead material, or a tab material, the tin layer 30 may be formed on both sides of the metal substrate 20. Furthermore, when the surface-treated metal sheet 10 for batteries according to this embodiment is used as a battery container such as a container or an electrode can, the tin layer 30 may be formed on the surface of the metal substrate 20 that faces the inner surface of the battery. The surface that faces the outer surface of the battery is not particularly limited, and may either have the tin layer 30 formed thereon or not have the tin layer 30 formed thereon.

[0023] <Metal Substrate 20> In this embodiment, the metal substrate 20 is iron-based. A steel plate is preferably used as the iron-based metal substrate 20. Examples of steel plates that can be used include low-carbon steel (carbon content: 0.01 to 0.15 wt %), ultra-low-carbon steel (carbon content: less than 0.01 wt %), and non-aging ultra-low-carbon steel obtained by adding Ti, Nb, or the like to ultra-low-carbon steel. Examples of metal substrates that can be used include electrolytic foils made of a pure metal selected from iron, copper, and nickel (electrolytic foils containing 99.9 wt % or more of a metal selected from iron, copper, and nickel), and electrolytic foils made of an alloy containing two or more metals selected from iron, copper, and nickel. When the surface-treated metal sheet 10 for a battery according to this embodiment is used as a negative electrode current collector, the metal substrate 20 may be a perforated plate or foil having through-holes.

[0024] In the metal substrate 20, the crystal orientation index Fe(200) of the (200) plane determined by X-ray diffraction measurement is preferably 2.55 or more, more preferably 3.00 or more, even more preferably 3.30 or more, and particularly preferably 3.50 or more. By controlling the crystal orientation index Fe(200) within the above range, when the tin layer 30 described below is formed on the metal substrate 20, defects (areas where the amount of tin adhesion is locally low) in the tin layer 30 on the metal substrate 20 side can be more suitably controlled, and therefore, when the surface-treated metal sheet for batteries 10 is used for batteries, the gas generation suppression effect during charge and discharge can be more excellent.

[0025] The crystal orientation index Fe(200) of the (200) plane of the metal base 20 can be determined as follows. The following description will be given in conjunction with the case where low carbon steel or ultra-low carbon steel is used as the metal base 20.

[0026] The crystal orientation index Fe(200) of the (200) plane of the metal substrate 20 can be determined by the method of Willson and Rogers (described in "K.S. Willson and J.A. Rogers; Tech. Proceeding Amer. Electroplaters Soc., 51, 92 (1964)"), after measuring the diffraction intensity of each crystal plane on the surface of the metal substrate 20 using an X-ray diffractometer with a CuKα radiation source, and then using the obtained diffraction intensity of iron and the diffraction intensity of a standard iron powder. It can be calculated based on the following formula (1). Note that, as the diffraction intensity data, data on the (110), (200), and (211) planes, which are said to appear within a diffraction angle (2θ) range of 30 to 90° when the X-ray source is CuKα, are used.

[0027] The crystal orientation index Fe(200) of the (200) plane of the metal base 20 can be calculated based on the following formula (2): Fe(200)=IF(200) / IFR(200) (2)

[0028] IF(200) and IFR(200) in the above formula (2) can be calculated based on the following formulas (3) and (4), respectively: IF(200) = I(200) / [I(110) + I(200) + I(211)] (3) IFR(200) = IR(200) / [IR(110) + IR(200) + IR(211)] (4)

[0029] In the above formula (2), IF(hkl) (h, k, and l are each an integer) represents the X-ray diffraction intensity ratio from the (hkl) plane, and IFR(hkl) represents the X-ray diffraction intensity ratio from the (hkl) plane of standard iron powder. In the above formula (3), I(hkl) represents the X-ray diffraction intensity from the (hkl) plane. In the above formula (4), IR(hkl) represents the X-ray diffraction intensity from the (hkl) plane of standard iron powder described in 03-065-4899 of the ICDD PDF-2 2014 database.

[0030] The thickness of the metal substrate 20 is not particularly limited, but is preferably 0.005 to 2.0 mm, more preferably 0.01 to 1.0 mm. For example, when used as a current collector, it is preferably 0.01 to 0.3 mm, more preferably 0.01 to 0.2 mm, and particularly preferably 0.01 to 0.1 mm. When used as a battery container or battery tab / lead material, it is preferably 0.1 to 1.2 mm, more preferably 0.1 to 1.0 mm, and particularly preferably 0.15 to 0.5 mm. As described below, the metal substrate 20 can be prepared by cold rolling and annealing an iron-based metal plate, and the thickness of the metal substrate 20 after cold rolling is preferably within the above range. The thickness of the metal substrate 20 is preferably measured by cross-sectional observation using an optical microscope or a scanning electron microscope (SEM). Furthermore, thickness measurement using a micrometer or the like can be applied before surface treatment, i.e., before the formation of the tin layer 30 described below.

[0031] In the metal base 20, it is preferable that at least the crystal orientation index Fe(200) of the (200) plane measured on the surface on which the tin layer 30 is formed is controlled to fall within the above-mentioned suitable range.

[0032] <Tin layer 30> As shown in Fig. 1 , the surface-treated metal sheet for batteries 10 of this embodiment includes a tin layer 30 formed on the surface of the metal substrate 20. The tin layer 30 can be formed by tin plating the metal substrate 20.

[0033] The tin layer 30 has a crystal orientation index Sn(200) of the (200) plane determined by X-ray diffraction measurement of less than 3.50, preferably 3.30 or less, more preferably 3.10 or less, and particularly preferably 3.00 or less. The lower limit of the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 is not particularly limited, but is usually 0.01 or more. The above-mentioned Sn(200) represents the crystal orientation index of the (200) plane of the tin layer 30. By setting the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 within the above range, defects near the surface of the tin layer 30 can be more suitably controlled, and therefore, when the surface-treated metal sheet for batteries 10 is used for batteries, the gas generation suppression effect during charge and discharge can be more excellent.

[0034] The crystal orientation index Sn(200) of the (200) plane of the tin layer 30 can be determined in the same manner as the method for determining the crystal orientation index of the metal substrate 20 described above. That is, the diffraction intensity of each crystal plane on the surface of the tin layer 30 is measured using an X-ray diffractometer with a CuKα radiation source, and then the obtained diffraction peaks of tin and the diffraction peaks of standard tin powder are used to calculate the crystal orientation index Sn(200) by the method of Willson and Rogers. The diffraction intensity data used is data on the (200) plane, (101), (220), (211), (301), (112), (400), (321), (420), (411), (312), and (501) planes, which are considered to appear within a diffraction angle (2θ) range of 30 to 90° when the X-ray source is CuKα. The crystal orientation index Sn(200) can be calculated by the Wilson and Rogers method based on the following formula (5): Sn(200)=IF(200) / IFR(200) (5)

[0035] In the above formula (5), IF(200) can be calculated by the following formula (6): IF(200) = I(200) / [I(200) + I(101) + I(220) + I(211) + I(301) + I(112) + I(400) + I(321) + I(420) + I(411) + I(312) + I(501)] (6)

[0036] In the above formula (5), IFR(200) can be calculated by the following formula (7): IFR(200) = IR(200) / [IR(200) + IR(101) + IR(220) + IR(211) + IR(301) + IR(112) + IR(400) + IR(321) + IR(420) + IR(411) + IR(312) + IR(501)] (7)

[0037] In the above formula (5), IF(200) represents the X-ray diffraction intensity ratio from the (200) plane, in the above formula (6), I(hkl) represents the X-ray diffraction intensity from the (hkl) plane, and in the formula (7), IR(hkl) represents the X-ray diffraction intensity from the (hkl) plane described in 00-004-0673 of the ICDD PDF-2 2014 database for standard tin powder.

[0038] The tin coverage in the tin layer 30 is preferably 1.0 g / m ２ More preferably, it is 2.0 g / m or more. ２ More preferably, 3.0 g / m ２ More preferably, 5.0 g / m ２ The upper limit of the amount of tin deposited in the tin layer 30 is not particularly limited, but is preferably 35.0 g / m ２ More preferably, it is 30.0 g / m or less. ２ More preferably 25.0 g / m or less ２ Particularly preferably 15.0 g / m or less ２ By setting the tin deposition amount in the tin layer 30 within the above range, gas generation during charge and discharge can be effectively suppressed. In particular, when the tin deposition amount in the tin layer 30 is 5.0 g / m or less, ２By controlling the tin content within the above range, it is possible to suitably control the crystal orientation index Sn(200) of the (200) plane of the tin layer 30. This makes it possible to more effectively suppress gas generation during charge and discharge. The amount of tin deposition can be determined by subjecting the surface-treated metal sheet for batteries 10 to X-ray fluorescence measurement or ICP emission spectroscopy. The above-mentioned amount of tin deposition represents the amount of tin deposition on one side of the metal substrate 20.

[0039] The thickness of the tin layer 30 is preferably 0.15 μm or more, more preferably 0.30 μm or more, even more preferably 0.50 μm or more, and particularly preferably 1.00 μm or more. The upper limit of the thickness of the tin layer 30 is not particularly limited, but is preferably 5.00 μm or less, more preferably 3.00 μm or less, even more preferably 2.50 μm or less, and particularly preferably 2.00 μm or less. By setting the thickness of the tin layer 30 within the above range, gas generation during charge and discharge can be effectively suppressed. In particular, by setting the thickness of the tin layer 30 to 1.00 μm or more, the gas generation suppression effect can be further enhanced. On the other hand, if the thickness of the tin layer 30 is below the lower limit of the above range, the crystal orientation index of the tin layer 30 cannot be appropriately controlled, and gas generation tends to become significant. The thickness of the tin layer 30 is determined by multiplying the tin deposition amount determined by the above method by the density of tin (g / cm ３ ) and converting it into a thickness (dividing the amount of tin deposition by the density), but the present invention is not limited to this, and other applicable methods include thickness measurement by cross-sectional observation with a scanning electron microscope (SEM), thickness measurement with a transmission electron microscope (TEM), and measurement with a high-frequency glow discharge optical emission spectrometer.

[0040] In the surface-treated metal sheet for batteries 10 of this embodiment, the ratio (Sn(200) / Fe(200)) of the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 to the crystal orientation index Fe(200) of the (200) plane of the metal substrate 20 satisfies 1.00 or less. The crystal orientation index ratio (Sn(200) / Fe(200)) is 1.00 or less, preferably 0.90 or less, and more preferably 0.80 or less. The lower limit of the crystal orientation index ratio (Sn(200) / Fe(200)) is not particularly limited, but is usually 0.01 or more. By setting the crystal orientation index ratio (Sn(200) / Fe(200)) within the above range, the surface-treated metal sheet for batteries 10 can be made to have an excellent gas generation suppression effect.

[0041] Furthermore, in the above-described metal substrate 20, when the crystal orientation index Fe(200) of the (200) plane determined by X-ray diffraction measurement is 2.55 or more, it is preferable that the crystal orientation index Fe(200) of the (200) plane of the metal substrate 20 and the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 further satisfy the following formula (1). By satisfying the following formula (1), the surface-treated metal sheet for batteries 10 can be made to have an excellent gas generation suppression effect. Sn(200)≦−(1 / Fe(200)−2.4)) / 2+3.4) (1)

[0042] In the surface-treated metal sheet for batteries 10 of this embodiment, the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 is less than 3.50, and the ratio (Sn(200) / Fe(200)) of the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 to the crystal orientation index Fe(200) of the (200) plane of the metal substrate 20 is 1.00 or less. The reason why such a configuration is preferable is as follows.

[0043] As mentioned above, one of the challenges facing the practical application of alkaline secondary batteries is the problem of hydrogen gas generation. Hydrogen gas is generated when the reaction conditions for hydrogen gas generation are met under conditions where a chemical reaction other than the battery reaction (self-discharge) occurs due to the formation of a local battery between dissimilar metals inside the battery. For example, in nickel-zinc batteries, zinc precipitates in the form of zinc or zinc oxide during charging and dissolves during discharge. However, zinc has one of the lowest potentials among metals used in aqueous batteries, so when a local battery state is formed between zinc and other metals used in the battery, the discharge rate is high, making it easy to meet the conditions for hydrogen gas generation.

[0044] Excessive hydrogen gas generation can lead to reduced battery performance and leakage problems. Specifically, when hydrogen gas generation occurs due to self-discharge, electrons that should contribute to the battery reaction are consumed by hydrogen gas generation, leading to reduced battery performance. The more hydrogen gas generated, the more the battery performance deteriorates. Furthermore, leakage may occur due to increased internal pressure, leading to reduced safety. Note that self-discharge here includes both side reactions during charging and discharging (chemical reactions including the hydrogen gas generation process) and chemical reactions that occur outside of charging and discharging, i.e., when the battery is left standing.

[0045] To avoid such problems as deterioration of battery performance and leakage, it is necessary to minimize the amount of hydrogen gas generated. In particular, the current collector material is a component that is more likely to generate hydrogen gas and is also more likely to self-discharge because zinc and other elements in the electrolyte are deposited on its surface and come into direct contact with it.

[0046] To address this problem, one known method for suppressing hydrogen gas generation is to use a material with a high hydrogen overvoltage, such as tin. However, the present inventors have confirmed that even when tin with a high hydrogen overvoltage is used, the effectiveness of suppressing hydrogen gas generation varies depending on the crystalline orientation of the tin layer. As a result of extensive research, the present inventors have found that gas generation in the surface-treated metal sheet for batteries 10 can be suppressed by setting the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 to less than 3.50 and setting the ratio of the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 to the crystal orientation index Fe(200) of the (200) plane of the metal substrate 20 (Sn(200) / Fe(200)) to 1.00 or less. The reason for this is unclear, but the following is thought to be the case. When tin plating is performed on a substrate, the manner of tin crystal growth and the extent of side reactions other than tin plating deposition vary depending on the crystal orientation of the metal constituting the substrate and the tin plating bath conditions. It is believed that defects with low tin deposition, such as voids, are formed locally within the tin plating when tin crystal growth is inappropriate or when side reactions occur to a large extent. Internal stress and strain in the tin plating can also cause defects to form within the tin plating. The crystal orientation index Sn(200) and the ratio of the crystal orientation indices (Sn(200) / Fe(200)) can be interpreted as indicators of the state of the tin plating. By controlling the crystal orientation index Sn(200) and the crystal orientation index Fe(200) to satisfy the above conditions, it is believed that the tin crystal growth and side reactions in the tin layer 30 are appropriately controlled, and the formation of defects within the tin layer 30 (from the metal substrate side to the surface side) is suppressed. The above-mentioned reasons are believed to be the reasons why the surface-treated metal sheet 10 for batteries in this embodiment has an excellent gas generation suppression effect.

[0047] On the other hand, the present inventors have found that gas generation tends to be more likely when the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 is 3.50 or more, or when the ratio of the crystal orientation indices (Sn(200) / Fe(200)) exceeds 1.00. The reason for this is not clear, but it is thought that this is because defects are formed in the tin layer 30, and part of the metal base 20 is exposed to the electrolyte due to the defects during charge and discharge, making gas generation more likely.

[0048] As mentioned above, the particularly preferred range of the tin coating amount in the tin layer 30 is 5.0 g / m ２ 15.0g / m or more ２ However, according to this embodiment, the tin deposition amount in the tin layer 30 is 3.0 g / m or less. ２ Even when the tin deposition amount in the tin layer 30 is relatively small, such as 1.0 g / m or less, by appropriately controlling the crystal orientation index Sn(200) and the crystal orientation index Fe(200), the surface-treated metal sheet for batteries 10 can have an excellent gas generation suppression effect. ２ 3.0g / m or more ２ When the crystal orientation index Sn(200) is 2.00 or less and the ratio of the crystal orientation indices (Sn(200) / Fe(200)) is 0.50 or less, the surface-treated metal plate 10 for batteries can be made to have an excellent gas generation suppression effect.

[0049] <Method for manufacturing surface-treated metal sheet 10 for batteries> The surface-treated metal sheet 10 for batteries according to this embodiment can be manufactured by tin-plating both surfaces of a metal substrate 20 to form a tin layer 30. In this embodiment, the tin layer 30 is formed on both surfaces of the metal substrate 20, but the present invention is not particularly limited to this embodiment, and it is sufficient that the tin layer 30 is formed on at least one surface of the metal substrate 20.

[0050] First, the metal substrate 20 is prepared using a metal plate. As the metal plate, it is preferable to use a steel plate, and in particular, it is more preferable to use a steel plate made of low carbon steel or ultra-low carbon steel. As a preparation method for obtaining the metal substrate 20, a method can be used in which the metal plate is subjected to cold rolling, followed by continuous annealing or box annealing. It is sufficient to perform one or more steps of cold rolling, and it is sufficient to perform one or more steps of continuous annealing or box annealing. Specific examples of methods for obtaining the metal substrate 20 include the following methods (i) to (vi). Primary cold rolling → Continuous annealing (i) Primary cold rolling → Box annealing (ii) Primary cold rolling → Continuous annealing → Secondary cold rolling (iii) Primary cold rolling → Continuous annealing → Secondary cold rolling → Continuous annealing (iv) Primary cold rolling → Continuous annealing → Secondary cold rolling → Box annealing (v) Primary cold rolling → Continuous annealing → Secondary cold rolling → Continuous annealing → Tertiary cold rolling (vi)

[0051] In the case of a metal substrate, from the viewpoint of easily and suitably controlling the crystal orientation index of the metal substrate, the reduction rate (%) during the first cold rolling is preferably 80% or more and 99% or less, more preferably 83% or more and 99% or less, and particularly preferably 85% or more and 95% or less. If the reduction rate exceeds the lower or upper limit, it becomes difficult to control the crystal orientation index Fe(200) of the metal substrate 20, which is not preferable. The reduction rate (%) refers to the reduction rate (%) of the thickness of the metal sheet before and after cold rolling, and can be determined by dividing the amount of change in the thickness of the metal sheet before and after cold rolling by the thickness of the metal sheet before cold rolling.

[0052] The reduction ratio (%) in the secondary cold rolling and the tertiary cold rolling is preferably 10% or more and 90% or less, more preferably 10% or more and 85% or less, and even more preferably 10% or more and 80% or less. By setting the reduction ratio (%) within the above range, the thickness of the metal substrate 20 can be made relatively thin, while the crystal orientation index Fe(200) can be suitably controlled and the strength of the metal substrate 20 can be increased. Therefore, the surface-treated metal sheet 10 for batteries can be made more suitable for use as a current collector. Note that, in order to further increase the strength of the metal substrate 20, the reduction ratio (%) is more preferably 45% or more and 85% or less, even more preferably 45% or more and 80% or less, and particularly preferably 50% or more and 80% or less.

[0053] Regarding the heat treatment conditions in continuous annealing, the heat treatment temperature is preferably 550°C or higher and 850°C or lower, and the heat treatment time is preferably 10 seconds or higher and 5 minutes or lower. Regarding the heat treatment conditions in continuous annealing, the heat treatment temperature is more preferably 600°C or higher and 800°C or lower, and the heat treatment time is more preferably 20 seconds or higher and 3 minutes or lower. Regarding the heat treatment conditions in box annealing, the heat treatment temperature is preferably 500°C or higher and 700°C or lower, and the heat treatment time is preferably 28,800 seconds or higher and 40,000 seconds or lower.

[0054] Note that, when box annealing is performed on a metal plate, it is possible to soften the metal plate, but it becomes difficult to suitably control the crystal orientation index Fe(200) of the resulting metal substrate 20. For this reason, among the above methods (i) to (vi), method (i), (iii), (iv), or (vi) using continuous annealing is preferred as a method for obtaining the metal substrate 20. In particular, method (iii), (iv), or (vi) using continuous annealing and performing cold rolling at least twice or more is more preferred from the viewpoint that the crystal orientation index Fe(200) of the metal substrate 20 can be suitably controlled and the thickness of the metal substrate can be easily adjusted appropriately depending on the required application.

[0055] The metal substrate 20 obtained by any of the methods (i) to (vi) above may be subjected to a shape modification treatment using a heat treatment, a tension leveler, etc. However, it is preferable that the crystal orientation index Fe(200) of the metal substrate 20 after the shape modification treatment is 2.55 or more.

[0056] Next, the surface of the metal substrate 20 is tin-plated to form a tin layer 30, thereby obtaining a surface-treated metal sheet for batteries 10. When forming the tin layer 30, the method for controlling the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 to be less than 3.50 is not particularly limited, but examples include a method of adding an additive to a tin plating bath used to form the tin layer 30, a method of adjusting and controlling the current density and treatment time of tin plating, or a method of using a tin plating bath containing an additive and adjusting the current density and treatment time of tin plating. In particular, it is preferable to use a tin plating bath containing an additive and adjust the tin coating weight of 3.0 g / m２ When the amount is relatively small, such as below, it is preferable to employ a method of adding an additive to the tin plating bath.

[0057] The tin plating bath used to form the tin layer 30 may be a ferrostane bath, an MSA bath, a halogen bath, a sulfuric acid bath, or the like, which further contains additives. Of these, a sulfuric acid bath having a bath composition of 10 to 60 g / L of tin ions and 25 to 110 mL / L of sulfuric acid and further containing additives is preferred. Furthermore, a bath composition of 10 to 60 g / L of tin ions and 25 to 60 mL / L of sulfuric acid and further containing the above-mentioned additives is particularly preferred.

[0058] Examples of additives that can be added to the tin plating bath include ethoxylated naphthol, ethoxylated naphthol sulfonic acid, polyoxyethylene naphthyl ether, and polyoxyethylene naphthyl ether sulfonic acid. Commercially available additives include Technistan TP Additive (manufactured by Technic Japan Co., Ltd.), UTB230R (manufactured by Ishihara Chemical Co., Ltd.), Noigen EN-10 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and TAA-F (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). When Technistan TP Additive or UTB230R is used as the additive, the amount of additive added to the tin plating bath is preferably 5 to 100 mL / L, more preferably 10 to 100 mL / L, and even more preferably 12 to 75 mL / L. In particular, by adding an additive in an amount of 12 to 75 mL / L, the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 can be more effectively controlled. When Noigen EN-10 or TAA-F is used as the additive, or when these are used in combination, the total amount of the additives added to the tin plating bath is preferably 5 to 50 g / L, more preferably 5 to 20 g / L.

[0059] Among the plating conditions for forming the tin layer 30, the current density is preferably 0.5 to 30.0 A / dm ２ and more preferably 1.0 to 30.0 A / dm ２ , more preferably 4.0 to 28.0 A / dm ２By setting the current density within the above range, the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 can be suitably controlled. The temperature of the plating bath is preferably 25 to 60°C, and more preferably 35 to 55°C. The pH of the plating bath is preferably 1.0 or less.

[0060] Among the plating conditions for forming the tin layer 30, the treatment time may be controlled so as to fall within the above-mentioned range of tin deposition amount while appropriately selecting the above-mentioned plating conditions. That is, the tin deposition amount is preferably 1.0 g / m ２ More preferably, 2.0 g / m ２ More preferably, 3.0 g / m ２ More preferably, 5.0 g / m ２ The treatment time may be adjusted so that the tin deposition amount is 35.0 g / m or more. ２ More preferably, it is 30.0 g / m or less. ２ More preferably 25.0 g / m or less ２ Below 15.0 g / m, particularly preferably ２ In particular, the treatment time is adjusted so that the tin deposition amount is 5.0 g / m. ２ By applying tin plating so as to satisfy the above conditions, it is possible to suitably control the crystal orientation index Sn(200) of the (200) plane of the tin layer 30, which is preferable.

[0061] When the above-mentioned additives are not added to the tin plating bath used to form the tin layer 30, it is preferable to use a metal substrate 20 prepared by any of the methods (i), (iii), (iv), and (vi) including continuous annealing, and to adjust the amount of tin deposited when forming the tin layer 30 to fall within a predetermined range. Specifically, the amount of tin deposited when forming the tin layer 30 is 3.0 g / m ２ 20.0g / m or more ２ More preferably, it is 3.5 g / m or less. ２ 15.0g / m or more ２It is more preferable that the following be satisfied: This makes it possible to suitably control the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 even when no additive is added to the tin plating bath.

[0062] When the metal substrate 20 is prepared by the method (ii) or (v) including box annealing, it is preferable to use a tin plating bath containing the above-mentioned additives and to set the tin coating weight within a predetermined range. In this case, the tin coating weight is preferably 3.0 g / m ２ 15.0g / m or more ２ More preferably, it is 3.5 g / m or less. ２ 10.0g / m or more ２ The following is the result.

[0063] The above method can provide a surface-treated metal sheet for batteries 10 including a metal substrate 20 with a suitably controlled crystal orientation index Fe(200) and a tin layer 30 with a suitably controlled crystal orientation index Sn(200). To more suitably control the crystal orientation index Fe(200) and the crystal orientation index Sn(200), the metal substrate 20 is prepared by any of the above methods (i), (iii), (iv), or (vi), and the tin layer 30 is formed using a tin plating bath containing 12 to 75 mL / L of Technistan TP Additive and / or UTB230R, or 5 to 20 g / L of Noigen EN-10 and / or TAA-F as additives, at a current density of 4.0 to 30.0 A / dm ２ Under the conditions, the tin deposition amount was 3.0 g / m ２ It is preferable to perform tin plating so that the above is achieved.

[0064] In the surface-treated metal sheet for batteries 10 according to this embodiment, as long as the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 and the ratio (Sn(200) / Fe(200)) of the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 to the crystal orientation index Fe(200) of the (200) plane of the metal substrate 20 are controlled within the above-mentioned ranges, a heat treatment such as a reflow treatment may be performed after the tin layer 30 is formed on the metal substrate 20. The reflow treatment is a process in which the sheet is heated to a temperature equal to or higher than the melting temperature of tin and then rapidly cooled.

[0065] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The methods for evaluating each property are as follows.

[0066] <X-ray Diffraction (XRD) Measurement (Crystal Orientation Index of Metal Substrate 20 and Tin Layer 30)> X-ray diffraction (XRD) measurement was performed on the surface-treated metal sheet for batteries 10 obtained in each example and comparative example to confirm the crystal orientation index of the metal substrate 20 and the tin layer 30. A Rigaku SmartLab was used as the X-ray diffraction measurement device, and the obtained surface-treated metal sheet for batteries 10 was cut into 30 mm x 30 mm samples to serve as measurement samples. The specific measurement conditions for the X-ray diffraction (XRD) measurement were as follows: (Apparatus configuration) X-ray source: CuKα Goniometer radius: 300 mm Optical system: focusing method (incident side slit system) Soller slit: 5° Longitudinal limiting slit: 5 mm Divergence slit: 1 / 2° (receiving side slit system) Scattering slit: 1 / 2° Soller slit: 5° Receiving slit: 0.3 mm Monochromatization method: counter monochromator method Detector: scintillation counter (Measurement parameters) Tube voltage-tube current: 45 kV 200 mA Scanning axis: 2θ / θ Scanning mode: continuous Measurement range: 2θ 30 to 90° Scanning speed: 10° / min Step: 0.05°

[0067] The obtained peak intensity values ​​were subjected to background subtraction using PDXL, an integrated powder X-ray analysis software manufactured by Rigaku Corporation, and data analysis was carried out.

[0068] For the surface-treated metal sheets for batteries 10 obtained in each example and comparative example, the diffraction intensity of each iron crystal plane on the surface of the metal substrate 20 was measured by the X-ray diffraction (XRD) measurement method described above, and then the obtained diffraction intensity of iron and the diffraction intensity of standard iron powder were used to determine the crystal orientation index Fe(200) of the (200) plane on the surface of the metal substrate 20. Note that the diffraction angles of each iron crystal plane and the diffraction angles of each crystal plane of the standard iron powder were those described in 03-065-4899 of the Diffraction ICDD PDF-2 2014 database.

[0069] For the surface-treated metal sheets for batteries 10 obtained in each example and comparative example, the diffraction intensity of each crystal plane of tin on the surface of the tin layer 30 was measured by the X-ray diffraction (XRD) measurement method described above, and then the obtained diffraction intensity of tin and the diffraction intensity of standard tin powder were used to determine the crystal orientation index of the (200) plane on the surface of the tin layer 30. Note that the diffraction angles of each crystal plane of tin and the diffraction angles of each crystal plane of the standard tin powder were those described in 00-004-0673 of the Diffraction ICDD PDF-2 2014 database.

[0070] The crystal orientation index ratio (Sn(200) / Fe(200)) was calculated using the determined crystal orientation indexes Fe(200) and Sn(200). Furthermore, it was determined whether the crystal orientation index Fe(200) and the crystal orientation index Sn(200) satisfied the above formula (1).

[0071] <Measurement of thickness of metal substrate 20> The surface-treated metal sheet for batteries 10 obtained in each example and comparative example was cut, and the cross section was polished. Then, the thickness of the metal substrate 20 was determined from an image obtained using a scanning electron microscope (manufactured by JEOL Ltd., model: JSM-IT500).

[0072] <Measurement of tin deposition amount of tin layer 30 and calculation of thickness> The tin deposition amount of the surface-treated metal sheet for batteries 10 obtained in each example and comparative example was quantified by a calibration curve method using X-ray fluorescence (XRF) measurement. The X-ray fluorescence device used was a ZSX Primus IV manufactured by Rigaku Corporation. In the X-ray fluorescence measurement, it was confirmed that the metal elements contained in the tin layer 30 of the surface-treated metal sheet for batteries 10 could be quantified by the calibration curve method. The thickness of the tin layer 30 was calculated by multiplying the tin deposition amount determined by the above method by the density of tin (g / cm ３ ) and converted into thickness (dividing the amount of tin deposited by the density).

[0073] <Evaluation of Gas Generation Inhibition by Corrosion Current Density Measurement> The gas generation inhibition effect was evaluated by measuring the corrosion current density when the surface-treated metal sheet 10 for batteries obtained in each Example and Comparative Example was immersed in an alkaline solution. Specifically, as a test simulating a local cell with deposited zinc, a zinc plate was used as the counter electrode, and the obtained surface-treated metal sheet 10 for batteries was immersed in an alkaline solution and the corrosion current density was measured using an electrochemical measurement system, thereby evaluating the gas generation inhibition. It can be determined that the smaller the corrosion current density 30 seconds after immersion in the alkaline solution, the higher the gas generation inhibition effect. The gas generation inhibition effect was evaluated as follows according to the corrosion current density value. A+: Corrosion current density 300 μA / cm ２ A: Corrosion current density 300 μA / cm ２ Super, 700μA / cm ２ B+: Corrosion current density 700 μA / cm ２ Super, 1500μA / cm ２ B: Corrosion current density 1500 μA / cm ２ Super, 2100μA / cm ２ C: Corrosion current density 2100 μA / cm ２ super

[0074] The corrosion current density measurement was carried out under the following conditions, and the corrosion current density (unit: μA / cm) generated between the test electrode and the counter electrode in a 30 wt % potassium hydroxide solution was measured. ２ ) was measured. Measuring device: HZ7000 manufactured by Hokuto Denko Corporation Test electrode: zinc plate (evaluation area 20 x 20 mm, thickness 0.5 mm) Counter electrode: measurement sample (measurement diameter φ6 mm) Measurement method: no-resistance ammeter

[0075] Example 1 First, a low-carbon aluminum-killed steel substrate was prepared having the following chemical composition: C: 0.04 wt %, Mn: 0.32 wt %, Si: 0.01 wt %, P: 0.012 wt %, S: 0.014 wt %, balance: Fe and unavoidable impurities.

[0076] Next, the prepared substrate was subjected to primary cold rolling at a rolling reduction of 85% to 95%, and then heat treatment by continuous annealing was carried out under conditions of a heat treatment temperature of 700° C., a soaking time of 60 seconds, and a reducing atmosphere.

[0077] Next, secondary cold rolling was performed at a rolling reduction of 40% to 50%, followed by heat treatment by continuous annealing at a heat treatment temperature of 700°C, a soaking time of 30 seconds, and in a reducing atmosphere, and then tertiary cold rolling was performed at a rolling reduction of 60% to 70% to obtain a metal substrate 20 (thickness: 0.06 mm). The rolling conditions and heat treatment conditions are shown in Table 1.

[0078] Next, the obtained metal substrate 20 was subjected to electrolytic degreasing and pickling by immersion in sulfuric acid, and then tin plating was performed under the following conditions to form a tin layer 30 on both sides of the metal substrate 20. The tin plating conditions were as follows. The tin plating treatment time was set under conditions such that the amount of tin deposited was the amount shown in Table 1, and a surface-treated metal sheet 10 for batteries was obtained. The obtained surface-treated metal sheet 10 for batteries was then subjected to the above-mentioned measurements. The results are shown in Table 2. (Bath composition) Stannous sulfate: 80 g / L Sulfuric acid: 80 g / L Additive (product name "UTB230R", manufactured by Ishihara Chemical Co., Ltd.): 15 mL / L (Plating conditions) pH: 1.0 or less Bath temperature: 45°C Current density: 5.0 A / dm ２

[0079] Example 2-4 A surface-treated metal sheet 10 for batteries was obtained in the same manner as in Example 1, except that tin plating was performed under the conditions shown in Table 1. The above-mentioned measurements were then carried out on the obtained surface-treated metal sheet 10 for batteries. The results are shown in Table 2.

[0080] Example 5 First, an ultra-low carbon aluminum-killed steel substrate was prepared, having the following chemical composition: C: 0.002 wt %, Mn: 0.2 wt %, Si: 0.01 wt %, P: 0.012 wt %, S: 0.014 wt %, balance: Fe and unavoidable impurities.

[0081] Next, the prepared substrate was cold-rolled at a rolling reduction of 85% to 95%, followed by heat treatment by continuous annealing at a heat treatment temperature of 700°C for a soaking time of 30 seconds in a reducing atmosphere, and then re-rolled (secondary cold rolling) at a rolling reduction of 60% to 70% to obtain a metal substrate 20 (thickness: 0.06 mm). The rolling conditions and heat treatment conditions are shown in Table 1.

[0082] Next, the surface-treated metal sheet for batteries 10 was obtained in the same manner as in Example 1, except that the obtained metal substrate 20 was tin-plated under the tin plating conditions shown in Table 1. The obtained surface-treated metal sheet for batteries 10 was then subjected to the above-mentioned measurements. The results are shown in Table 2.

[0083] Example 6 A low-carbon aluminum-killed steel substrate having the same chemical composition as in Example 1 was prepared, except that the thickness of the substrate was changed. This substrate was cold-rolled at a reduction ratio of 85% to 95%, and then heat-treated by continuous annealing at a heat treatment temperature of 700°C for a soaking time of 30 seconds in a reducing atmosphere. The substrate was then re-rolled at a reduction ratio of 70% to 80%, to obtain a metal substrate 20 (thickness: 0.04 mm). The rolling conditions and heat-treatment conditions are shown in Table 1.

[0084] Next, the obtained metal substrate 20 was subjected to electrolytic degreasing and pickling by immersion in sulfuric acid, and then tin plating was performed under the following conditions to form a tin layer 30 on both sides of the metal substrate 20. The tin plating conditions were as follows. The tin plating treatment time was set under conditions such that the amount of tin deposited was the amount shown in Table 1, and a surface-treated metal sheet 10 for batteries was obtained. The obtained surface-treated metal sheet 10 for batteries was then subjected to the above-mentioned measurements. The results are shown in Table 2. (Bath composition) Tin ions: 20 g / L Sulfuric acid: 45 mL / L Additive (product name "Technistan TP Additive", manufactured by Technic Japan Co., Ltd.): 50 mL / L (Plating conditions) pH: 1.0 or less Bath temperature: 45°C Current density: 5.0 A / dm ２

[0085] Example 7 A metal substrate 20 was obtained in the same manner as in Example 5, except that the reduction ratio in the secondary cold rolling was changed as shown in Table 1 for an ultra-low carbon aluminum-killed steel substrate prepared in the same manner as in Example 5, and the second continuous annealing and the third cold rolling were not performed. A tin layer 30 was formed on both sides of the metal substrate 20 in the same manner as in Example 6, except that the tin plating conditions were changed as shown in Table 1, to obtain a surface-treated metal sheet 10 for batteries. The above-mentioned measurements were performed on the obtained surface-treated metal sheet 10 for batteries. The results are shown in Table 2.

[0086] Example 8: An ultra-low carbon aluminum-killed steel substrate prepared in the same manner as in Example 5 was cold-rolled at a rolling reduction of 80% to 90%, followed by heat treatment by continuous annealing at a heat treatment temperature of 785°C for a soaking time of 60 seconds in a reducing atmosphere to obtain a metal substrate 20. The obtained metal substrate 20 was subjected to electrolytic degreasing and pickling by immersion in sulfuric acid, and then tin plating was performed under the following conditions to form a tin layer 30 on both sides of the metal substrate 20. The tin plating conditions were as follows. The tin plating treatment time was set so that the tin deposition amount was the amount shown in Table 2. Thereafter, the entire substrate was heated at 240°C for 7 seconds, followed by rapid cooling with water, thereby performing a reflow treatment to obtain a surface-treated metal sheet 10 for a battery. The obtained surface-treated metal sheet 10 for a battery was then subjected to the above-mentioned measurements. The results are shown in Table 2. (Bath composition) Tin ions: 25 g / L Sulfuric acid: 15 mL / L Additive (product name "Noigen EN-10", manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.): 5.7 g / L Additive (product name "TAA-F", manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.): 3.4 g / L (Plating conditions) pH: 1.0 or less Bath temperature: 42°C Current density: 26.0 A / dm ２

[0087] Example 9 A surface-treated metal sheet 10 for batteries was obtained and evaluated in the same manner as in Example 8, except that the tin plating conditions were changed as shown in Table 1. The results are shown in Table 2.

[0088] Examples 10 to 12 Surface-treated metal sheets 10 for batteries were obtained and evaluated in the same manner as in Example 6, except that the tin plating conditions were changed as shown in Table 1. The results are shown in Table 2.

[0089] <Examples 13, 16, 20-25> Surface-treated metal sheets 10 for batteries were obtained and evaluated in the same manner as in Example 5, except that the continuous annealing conditions, the secondary cold rolling reduction, and the tin plating conditions were changed as shown in Table 1. The results are shown in Table 2.

[0090] <Examples 14 and 17> Surface-treated metal sheets 10 for batteries were obtained and evaluated in the same manner as in Example 5, except that the conditions for continuous annealing and cold rolling, and the conditions for tin plating were changed as shown in Table 1. The results are shown in Table 2.

[0091] Examples 15, 18-19 For a low-carbon aluminum-killed steel substrate prepared in the same manner as in Example 6, a metal substrate 20 was obtained in the same manner as in Example 6, except that the reduction ratios in continuous annealing and secondary cold rolling were changed as shown in Table 1. A surface-treated metal sheet for batteries 10 was obtained in the same manner as in Example 1, and evaluations were similarly performed, except that the tin plating conditions were changed as shown in Table 1. The results are shown in Table 2.

[0092] Examples 26-27 A metal substrate 20 was obtained in the same manner as in Example 8, except that the low-carbon aluminum-killed steel used in Example 1 was used as the substrate and the continuous annealing conditions were changed as shown in Table 1. A surface-treated metal sheet 10 for batteries was obtained in the same manner as in Example 6, except that the tin plating conditions were changed as shown in Table 1, and was evaluated in the same manner. The results are shown in Table 2.

[0093] Example 28 The low-carbon aluminum-killed steel substrate used in Example 1 was subjected to primary cold rolling at a rolling reduction of 80% to 90%, followed by heat treatment by continuous annealing at a heat treatment temperature of 700°C, a soaking time of 30 seconds, and a reducing atmosphere. Subsequently, secondary cold rolling was performed at a rolling reduction of 40% to 50%, followed by heat treatment by box annealing at a heat treatment temperature of 600°C, a soaking time of 36,000 seconds, and a reducing atmosphere, thereby obtaining a metal substrate 20. A tin layer 30 was formed on the obtained metal substrate 20 in the same manner as in Example 6, except that the tin plating conditions were changed as shown in Table 1. A surface-treated metal sheet for batteries 10 was obtained and evaluated in the same manner. The results are shown in Table 2.

[0094] Comparative Example 1 A surface-treated metal sheet 10 for batteries was obtained and evaluated in the same manner as in Example 6, except that the tin plating conditions were changed as shown in Table 1. The results are shown in Table 2.

[0095] Comparative Examples 2-5, 8-9 Surface-treated metal sheets 10 for batteries were obtained and evaluated in the same manner as in Example 28, except that the tin plating conditions were changed as shown in Table 1. The results are shown in Table 2.

[0096] Comparative Examples 6-7 A metal substrate 20 was prepared and a tin layer 30 was formed in the same manner as in Example 28, except that the tin plating conditions were changed as shown in Table 1. The entire substrate was then heated at 240°C for 8 seconds and quenched by pouring water over it to perform a reflow treatment, thereby obtaining a surface-treated metal sheet for batteries 10. The surface-treated metal sheet for batteries 10 was evaluated in the same manner as in Example 28. The results are shown in Table 2.

[0097]

[0098]

[0099] As shown in Table 2, the surface-treated metal sheet 10 for batteries in which the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 was less than 3.50 and the ratio of the crystal orientation index Sn(200) to the crystal orientation index Fe(200) of the (200) plane of the metal substrate 20 (Sn(200) / Fe(200)) was 1.00 or less had a small corrosion current density and an excellent gas generation suppression effect.

[0100] In particular, the metal substrate 20 is prepared by any one of the above methods (i), (iii), (iv), or (vi), and the tin layer 30 is formed using a tin plating bath containing, as an additive, Technistan TP Additive and / or UTB230R at 12 to 75 mL / L, or Noigen EN-10 and / or TAA-F at 5 to 20 g / L, at a current density of 4.0 to 30.0 A / dm ２ The surface-treated metal sheets 10 for batteries in Examples 1-9 and 13-27 obtained by tin plating to satisfy the conditions above had a crystal orientation index Sn(200) controlled to 3.30 or less, and were more effective in suppressing gas generation. The surface-treated metal sheets 10 for batteries in Examples 7 and 26-27 had a tin deposition amount of 3.0 g / m ２ Although the amount of tin deposition was relatively small at 3.0 g / m or less, the crystal orientation index Sn(200) was controlled to 2.00 or less and the ratio of the crystal orientation indices (Fe(200) / Sn(200)) was controlled to 0.50 or less, and thus the gas generation suppression effect was excellent. ２The surface-treated metal sheets 10 for batteries in Examples 1-6, 8-9, and 13-25 obtained by tin plating as described above were significantly superior in gas generation suppression effect.

[0101] On the other hand, when the crystal orientation index Sn(200) of the (200) plane of the tin layer 30 was 3.50 or more, or the ratio of the crystal orientation indices (Sn(200) / Fe(200)) exceeded 1.00, as in Comparative Example 1-9, the corrosion current density was very large, resulting in a significantly poorer gas generation suppression effect.

[0102] 10... Surface-treated metal sheet for battery 20... Metal substrate 30... Tin layer

Claims

1. A surface-treated metal sheet for batteries comprising: an iron-based metal substrate; and a tin layer provided on at least one side of the metal substrate, wherein the tin layer has a crystal orientation index Sn(200) of the (200) plane of less than 3.50; and the ratio of the crystal orientation index Sn(200) to the crystal orientation index Fe(200) of the (200) plane of the metal substrate (Sn(200) / Fe(200)) is 1.00 or less.

2. The surface-treated metal sheet for batteries according to claim 1, wherein the crystal orientation index Fe(200) is 2.55 or more.

3. The surface-treated metal sheet for batteries according to claim 2, wherein the crystal orientation index Fe(200) and the crystal orientation index Sn(200) satisfy the following formula (1): Sn(200)≦−(1 / Fe(200)−2.4) / 2+3.4) (1) 4. The surface-treated metal sheet for batteries according to any one of claims 1 to 3, wherein the metal substrate is a steel sheet.

5. The surface-treated metal sheet for batteries according to claim 4, wherein the steel sheet is low-carbon steel or ultra-low-carbon steel.

6. The surface-treated metal sheet for batteries according to any one of claims 1 to 5, wherein the crystal orientation index Sn(200) is 3.30 or less.

7. The tin coating amount in the tin layer is 3.0 g / m ２ Above, 35.0g / m ２ The surface-treated metal sheet for batteries according to any one of claims 1 to 6, wherein:

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