Surface-treated metal plate for water-based batteries

Abstract

To provide a surface-processed metal plate for a battery, which is capable of suppressing gas generation and which is superior in resistance against electrolyte solution.SOLUTION: Provided is a surface-processed metal plate for a battery comprising: a base material composed of a metal plate arranged on the basis of iron or nickel; and a nickel-tin alloy layer at least on one face of the metal plate. The nickel-tin alloy layer contains Ni3Sn4 as an alloy phase.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a surface-treated metal sheet for batteries that can suppress gas generation and has excellent electrolyte resistance. [Background technology]

[0002] Among the types of rechargeable batteries that use an alkaline aqueous solution as the electrolyte, so-called alkaline batteries, nickel-cadmium batteries and nickel-metal hydride batteries are widely known and have been put into practical use. Furthermore, among alkaline rechargeable batteries, air batteries and nickel-zinc batteries, which use nickel hydroxide or similar material for the positive electrode, zinc or similar material for the negative electrode active material, and an alkaline aqueous solution as the electrolyte, are being actively developed as next-generation batteries.

[0003] The advantages of nickel-zinc batteries include their high electromotive force and high energy density compared to other water-based batteries, the low cost of zinc, the absence of rare metals, the fact that both nickel and zinc are recyclable metals, and their superior safety compared to lithium-ion batteries due to the use of a water-based electrolyte.

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

[0005] It is conventionally known that the hydrogen gas generation problem described above can be solved by applying a material with a high hydrogen overpotential to the negative electrode current collector. For example, Patent Document 1 attempts to solve the hydrogen gas generation problem described above by increasing the hydrogen overpotential by using a copper-tin alloy as the material for the negative electrode current collector. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2-75160 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the technology described in Patent Document 1 above had insufficient corrosion resistance (electrolyte resistance) when used in practical alkaline secondary batteries. In other words, in order to achieve sufficient battery performance as an alkaline secondary battery, the concentration of potassium hydroxide in the electrolyte is preferably 20% by weight or more, and for even higher performance, it is desirable to have a concentration of 25-40% by weight. On the other hand, while copper-tin alloys like the one described in Patent Document 1 above offer improved corrosion resistance compared to pure copper, they still dissolve in high-concentration electrolyte environments as described above, and dissolution is further accelerated during discharge reactions, making them unsuitable for practical use.

[0008] On the other hand, when using nickel, which is generally considered to have excellent alkali resistance, dissolution in alkaline electrolytes can be suppressed, but nickel has a low hydrogen overpotential, which makes it prone to generating hydrogen gas. In particular, when zinc is involved in the battery reaction, the potential difference between zinc and nickel in the alkaline electrolyte is large, making it significantly easier for hydrogen gas to be generated.

[0009] In view of the above problems, the present inventors diligently studied to develop a surface-treated metal plate for batteries that can suppress gas generation during charging and discharging of alkaline secondary batteries and suppress dissolution into the electrolyte, and which can be used as a current collector material for the negative electrode, battery tab / lead material, and battery container (battery casing material). As a result, they found that it is possible to solve all of the above problems by giving the surface-treated metal plate for batteries a specific configuration, and thus conceived the present invention. [Means for solving the problem]

[0010] The inventors conducted diligent studies to achieve the above objective and found that a surface-treated metal plate for batteries, comprising a nickel-tin alloy layer on at least one side of a metal plate based on iron or nickel, can achieve the above objective, thus completing the present invention.

[0011] In other words, the present invention relates to the following matters. [1] A surface-treated metal plate for a battery, wherein the base material of the surface-treated metal plate for a battery is a metal plate based on iron or nickel, and the metal plate is provided with a nickel-tin alloy layer on at least one side.

[0012] [2] The surface-treated metal plate for batteries according to [1], wherein the thickness of the nickel-tin alloy layer, as measured by high-frequency glow discharge surface analysis (GDS), is 0.05 to 5.00 μm. [3] A surface-treated metal plate for a battery according to [1] or [2], comprising a nickel layer below the nickel-tin alloy layer. [4] The amount of nickel deposited on the surface on which the nickel-tin alloy layer is formed is 2.1 to 65.0 g / m². 2 A surface-treated metal plate for batteries as described in any of [1] to [3]. [5] The amount of tin deposited on the surface on which the nickel-tin alloy layer is formed is 0.05 to 15.0 g / m². 2 A surface-treated metal plate for batteries as described in any of [1] to [4].

[0013] [6] A surface-treated metal sheet for batteries according to any one of [1] to [5], wherein the nickel-tin alloy layer contains Ni3Sn4 as an alloy phase. [7] A surface-treated metal plate for a battery according to any one of [1] to [6], wherein the nickel-tin alloy layer contains, as an alloy phase, a nickel-tin alloy in which diffraction peaks are obtained in at least one of the ranges of diffraction angle 2θ = 40 to 42° or diffraction angle 2θ = 46 to 48° by X-ray diffraction measurement using CuKα as a source. [8] The nickel-tin alloy layer contains, as an alloy phase, a nickel-tin alloy that yields diffraction peaks in the diffraction angle range 2θ = 40 to 42° and the diffraction angle range 2θ = 46 to 48°. [7] Surface-treated metal plate for batteries. [9] A surface-treated metal sheet for batteries according to any one of [1] to [8], wherein the nickel-tin alloy layer contains Ni3Sn2 as an alloy phase.

[10] A surface-treated metal plate for a battery according to any one of [1] to [9], wherein the metal plate is made of low carbon steel or ultra-low carbon steel.

[11] The metal plate is an electrolytic foil made of pure iron, an electrolytic foil made of pure nickel, or an electrolytic foil made of a binary alloy of iron and nickel, according to any one of [1] to

[10] . [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a surface-treated metal plate for batteries that can suppress gas generation and has excellent electrolyte resistance. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a cross-sectional view of a surface-treated metal plate for a battery according to an embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view of a surface-treated metal plate for a battery according to another embodiment of the present invention. [Figure 3A] Figure 3A is an X-ray diffraction (XRD) chart showing the diffraction peaks of Ni-Sn40-42 or Ni-Sn46-48. [Figure 3B] Figure 3B is an X-ray diffraction (XRD) chart showing the diffraction peaks of Ni3Sn4. [Figure 3C] Figure 3C is an X-ray diffraction (XRD) chart showing the diffraction peaks of Ni3Sn2. [Figure 3D] Figure 3D is an X-ray diffraction (XRD) chart showing the diffraction peaks of Ni-Sn40-42 before and after the anode reaction test. [Figure 3E]Figure 3E is an X-ray diffraction (XRD) chart showing the diffraction peaks of Ni-Sn46-48 before and after the anode reaction test. [Figure 4] Figure 4 is a diagram illustrating the method for measuring thickness using high-frequency glow discharge surface spectroscopy (GDS). [Figure 5] Figure 5(A) is a graph obtained by GDS measurement for the surface-treated metal plate for battery of Example 1, and Figures 5(B) and 5(C) are graphs obtained by GDS measurement for the surface-treated metal plate for battery of Example 5. [Modes for carrying out the invention]

[0016] The surface-treated metal sheet for batteries of the present invention is a surface-treated metal sheet used for battery applications, for example, as a current collector for the positive or negative electrode, or as a battery container for housing the power generation element of a battery. The battery is not particularly limited, but examples include aqueous batteries using alkaline electrolytes, such as nickel-cadmium batteries, nickel-metal hydride batteries, zinc-air batteries, and nickel-zinc batteries, and non-aqueous batteries such as lithium-ion batteries. The surface-treated metal sheet for batteries of the present invention is suitably used in aqueous batteries, and is particularly suitable for use as a current collector or battery container for aqueous batteries in which zinc is involved in the battery reaction (for example, nickel-zinc batteries). Furthermore, this invention can be applied to either primary or secondary batteries, as long as they are aqueous batteries. An embodiment of the present invention will be described below with reference to the drawings.

[0017] Figure 1 is a cross-sectional view of a surface-treated metal plate 10 for a battery according to an embodiment of the present invention. As shown in Figure 1, the surface-treated metal plate 10 for a battery according to this embodiment has nickel-tin alloy layers 40 on both sides of a base material 20. Although Figure 1 illustrates a configuration in which the nickel-tin alloy layer 40 is formed via a nickel layer 30 formed on the base material 20, the invention is not particularly limited to this configuration, and for example, the nickel-tin alloy layer 40 may be formed directly on the base material 20.

[0018] Furthermore, while Figure 1 illustrates an embodiment in which the nickel-tin alloy layer 40 is formed on both sides of the base material 20, in this embodiment, it is sufficient for the nickel-tin alloy layer 40 to be formed on at least one side of the base material 20, and it is not particularly limited to the case in which the nickel-tin alloy layer 40 is formed on both sides. In addition, in this embodiment, the nickel-tin alloy layer 40 may be formed on the side where gas generation suppression is required. For example, when the surface-treated metal plate 10 for batteries according to this embodiment is used as a current collector for the positive or negative electrode (for example, as a current collector for the negative electrode of a nickel-zinc battery), or as a lead material or tab material, the nickel-tin alloy layer 40 can be formed on both sides of the base material 20. Furthermore, when the surface-treated metal plate 10 for batteries according to this embodiment is used as a battery container such as a container or electrode can, the nickel-tin alloy layer 40 can be formed on the surface of the base material 20 that faces the inner surface of the battery. In particular, if the structure is such that the inner surface of the battery is exposed to the negative electrode potential, it is desirable that the nickel-tin alloy layer 40 be formed on the inner surface of the battery. The surface that faces the outer surface of the battery is not particularly limited, but it can be left untreated, or other surface-treated layers such as the nickel layer 30 or the nickel-tin alloy layer 40 can be formed on it.

[0019] <Base material 20> The base material 20 can be any metal plate based on iron or nickel, and is not particularly limited. For example, steel plates such as low-carbon steel (carbon content 0.01 to 0.15 wt%), ultra-low-carbon steel with a carbon content of 0.003 wt% or less, non-aging ultra-low-carbon steel obtained by adding Ti or Nb to ultra-low-carbon steel, or nickel plates can be used. Among these, low-carbon steel and ultra-low-carbon steel can be preferably used. Other examples of base material 20 include electrolytic foil made of pure iron (electrolytic foil with an iron content of 99.9 wt% or more), electrolytic foil made of pure nickel (electrolytic foil with a nickel content of 99.9 wt% or more), or electrolytic foil made of a binary alloy of iron and nickel. Furthermore, when the surface-treated metal plate 10 for batteries according to this embodiment is used as a current collector for the positive or negative electrode, the base material 20 may be a perforated plate or perforated foil having through holes.

[0020] The thickness of the base material 20 is not particularly limited, but for example, when used as a current collector, it is preferably 0.005 to 2.0 mm, more preferably 0.01 to 0.8 mm, even more preferably 0.025 to 0.8 mm, and especially preferably 0.025 to 0.3 mm. When used as a battery container, it is preferably 0.1 to 2.0 mm, more preferably 0.15 to 0.8 mm, and even more preferably 0.15 to 0.5 mm.

[0021] <Nickel-tin alloy layer 40> The surface-treated metal plate 10 for batteries in this embodiment includes a nickel-tin alloy layer 40 on a substrate 20. Figure 1 shows an embodiment in which the nickel-tin alloy layer 40 is formed on the substrate 20 via a nickel layer 30, but the embodiment is not particularly limited to this form, and a configuration without a nickel layer 30 is also possible. The presence or absence of the nickel-tin alloy layer 40 can be confirmed by performing high-frequency glow discharge surface analysis (GDS) and X-ray diffraction (XRD) measurements, which will be described later.

[0022] The nickel-tin alloy layer 40 may be formed from an alloy of nickel and tin, but from the viewpoint of appropriately achieving the effects of this embodiment, it is preferable that it be a binary alloy of nickel and tin, and that it substantially does not contain other elements such as iron. For example, the surface-treated metal plate 10 for the battery in this embodiment may have an iron-nickel-tin ternary alloy layer, but it is preferable that it has at least a layer made of a binary alloy of nickel and tin.

[0023] The nickel-tin alloy layer 40 is preferably a binary alloy of nickel and tin, and its crystal structure is not particularly limited, but the alloy phase should be a nickel-tin alloy from which diffraction peaks are obtained in the diffraction angle range of 2θ = 40~42° by X-ray diffraction measurement using Ni3Sn4, Ni3Sn2, or CuKα as the source (hereinafter, this nickel-tin alloy will be referred to as "Ni-Sn"). 40-42 (hereinafter referred to as "Ni-Sn"), or a nickel-tin alloy from which diffraction peaks are obtained in the diffraction angle range of 2θ = 46~48° (hereinafter referred to as "Ni-Sn") 46-48 It is preferable that it contains ) The above Ni-Sn 40-42 , and Ni-Sn 46-48 However, to confirm that it is a binary alloy of nickel and tin, this can be confirmed using methods such as radiofrequency glow discharge surface spectroscopy (GDS) or scanning Auger electron spectroscopy (AES), which will be described later. Specifically, from the nickel-tin alloy layer 40 formed on the substrate 20, radiofrequency glow discharge surface spectroscopy (GDS) is used to confirm that Ni intensity, Sn intensity, and Fe intensity can be obtained. Next, by X-ray diffraction (XRD) measurement, if diffraction peaks are obtained in the diffraction angle range 2θ = 40 to 42° or in the diffraction angle range 2θ = 46 to 48°, it can be determined that a binary alloy of nickel and tin is contained. Furthermore, it was confirmed that the diffraction peaks in the diffraction angle range 2θ = 40 to 42°, and the diffraction peaks in the diffraction angle range 2θ = 46 to 48°, differed from the diffraction peaks of pure nickel, pure tin, and pure iron.

[0024] As an alloy phase, Ni3Sn4 can obtain a diffraction peak of the (310) plane in the range of diffraction angle 2θ = 31 to 32° by X-ray diffraction measurement using CuKα as the radiation source (according to ICDD PDF card 03-065-4553). For Ni3Sn4 as an alloy phase, it can also be confirmed from the diffraction peak of the (-311) plane in the range of diffraction angle 2θ = 32.5 to 33.5° and the diffraction peak of the (002) plane in the range of diffraction angle 2θ = 35 to 36° (according to ICDD PDF card 03-065-4553).

[0025] As an alloy phase, Ni3Sn2 can obtain a diffraction peak of the (201) plane in the range of diffraction angle 2θ = 54 to 55° by X-ray diffraction measurement using CuKα as the radiation source (according to ICDD PDF card 01-072-2561). For Ni3Sn2 as an alloy phase, it can also be confirmed from the diffraction peak of the (002) plane in the range of diffraction angle 2θ = 34 to 35° (according to ICDD PDF card 01-072-2561).

[0026] Also, Ni-Sn as an alloy phase 40-42 can obtain a diffraction peak in the range of diffraction angle 2θ = 40 to 42° by X-ray diffraction measurement using CuKα as the radiation source, and Ni-Sn as an alloy phase 46-48 can obtain a diffraction peak in the range of diffraction angle 2θ = 46 to 48°.

[0027] The nickel-tin alloy layer 40 preferably contains, as an alloy phase, any one of Ni3Sn4, Ni3Sn2, Ni-Sn 40-42 , and Ni-Sn 46-48 . More preferably, from the viewpoint of further enhancing the electrolytic solution resistance, it preferably contains at least one of Ni3Sn4 and Ni3Sn2 as an alloy phase. From the viewpoint of further enhancing the gas generation suppression effect, it preferably contains at least one of Ni3Sn4, Ni-Sn , and Ni-Sn 40-42 , and Ni-Sn 46-48 as an alloy phase. In particular, Ni-Sn 40-42 and Ni-Sn46-48 When both of these are included, the gas generation suppression effect is significantly enhanced, which is particularly preferable. Furthermore, from the viewpoint of further enhancing the gas generation suppression effect and electrolyte resistance, it is particularly preferable to include Ni3Sn4 as the alloy phase. Note that the nickel-tin alloy layer 40 contains Ni3Sn4, Ni3Sn2, and Ni-Sn as the alloy phase. 40-42 , and Ni-Sn 46-48 It may contain two or more of these. The nickel-tin alloy layer 40 consists of Ni3Sn4, Ni3Sn2, and Ni-Sn 40-42 , and Ni-Sn 46-48 Preferably, alloying phases other than the alloying phase (for example, Ni3Sn) are not included, meaning that in X-ray diffraction measurements using CuKα as a source, diffraction peaks should not be obtained in the diffraction angle range 2θ = 33~34° (more specifically, Ni3Sn4, Ni3Sn2, Ni-Sn 40-42 , and Ni-Sn 46-48 It is preferable that a diffraction peak with an integrated intensity of 1% or more of the integrated intensity of the peak with the largest integrated intensity among the corresponding peaks is not obtained.

[0028] The reasons why having the above configuration is desirable in this embodiment are as follows. In other words, as mentioned above, one of the challenges to the practical application of alkaline secondary batteries is the problem of hydrogen gas generation. Hydrogen gas is generated when the conditions for hydrogen gas generation are met under conditions where chemical reactions other than the battery reaction (self-discharge) occur, for example, due to the formation of a local galvanic cell between dissimilar metals inside the battery. For example, in nickel-zinc batteries, zinc is deposited in the form of zinc or zinc oxide during charging, and this zinc dissolves during discharge. However, since zinc is one of the metals with a low potential among the metals used in aqueous batteries, the amount of discharge when a local galvanic cell state is formed between it and other metals used in the battery is large, making it easy to meet the conditions for hydrogen gas generation.

[0029] Excessive hydrogen gas generation can lead to decreased battery performance and leakage problems. Specifically, when hydrogen gas is generated due to self-discharge, electrons that should be contributing to the battery reaction are consumed by the hydrogen gas generation, leading to a decrease in battery performance. The more hydrogen gas generated, the greater the decrease in battery performance. Furthermore, leakage may occur due to an increase in internal pressure, leading to a decrease in 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., in a state of natural standing.

[0030] To avoid such battery performance degradation and leakage problems, it is necessary to minimize hydrogen gas generation. Current collector materials, in particular, are prone to hydrogen gas generation because zinc and other elements from the electrolyte precipitate on their surface and come into direct contact with it, and they are also prone to self-discharge.

[0031] One known method for reducing such gas generation is to apply materials with high hydrogen overpotential. In this embodiment, the tin in the nickel-tin alloy layer 40 is a material with high hydrogen overpotential. However, tin has low electrolyte resistance. On the other hand, the nickel in the nickel-tin alloy layer 40 has low hydrogen overpotential but excellent electrolyte resistance. Therefore, the inventors modified the plating conditions and heat treatment conditions for forming the nickel-tin alloy layer 40 to obtain alloy layers with different nickel and tin content and alloy structures. Through diligent research and repeated experiments, the inventors discovered that by incorporating the nickel-tin alloy layer 40, the aforementioned problems of electrolyte resistance and hydrogen gas generation can be simultaneously solved. Furthermore, the nickel-tin alloy layer 40 contains Ni3Sn4, Ni3Sn2, and Ni-Sn as alloy phases. 40-42 , and Ni-Sn 46-48 It is preferable that the alloy phase contains at least one of the above, and we have found that when the alloy phase containing Ni3Sn4 is included, the electrolyte resistance and gas generation suppression effect are superior.

[0032] The thickness of the nickel-tin alloy layer 40 is not particularly limited, but is preferably 0.05 to 5.00 μm, more preferably 0.05 to 3.00 μm, and even more preferably 0.10 to 2.50 μm. By setting the thickness of the nickel-tin alloy layer 40 within the above range, the gas generation suppression effect and electrolyte resistance can be further enhanced.

[0033] The thickness of the nickel-tin alloy layer 40 can be determined by performing high-frequency glow discharge emission surface analysis (GDS) using a high-frequency glow discharge emission spectrometer (GDS measuring device). Here, high-frequency glow discharge emission spectrometer is an analytical method that performs elemental analysis in the depth direction of samples that have undergone various surface treatments such as plating and heat treatment, and is a destructive analysis by sputtering.

[0034] The measurement method using a high-frequency glow discharge emission spectrometer is as follows: First, two standard samples are prepared: one with a pure Ni plating layer of known thickness formed on an iron-based metal plate, and another with a pure Sn plating layer of known thickness formed on a stainless steel plate with strike Ni plating. Next, measurements are performed using the high-frequency glow discharge emission spectrometer on these two standard samples to obtain Ni intensity data, Sn intensity data, and Fe intensity data at each depth position. Then, from the obtained Ni intensity data, Sn intensity data, and Fe intensity data, the relationship between sputtering depth and sputtering time (etching rate (unit: μm / sec)) is determined, and this is expressed as the etching rate R of the pure Ni plating layer. Ni , etching rate R of the pure Sn plating layer Sn Furthermore, the pure Ni plating layer and the nickel-tin alloy layer have similar hardness values, and measurements using a high-frequency glow discharge emission spectrometer show a correlation between the etching rate and hardness. Ni The etching rate R of the nickel-tin alloy layer Ni-Sn Let's assume that.

[0035] Next, the Ni, Sn, and Fe intensity data obtained from the measurements of the two standard samples described above are corrected so that their respective maximum values ​​become equivalent. The correction of the intensity data is performed by determining a correction coefficient that makes each of the maximum values ​​equivalent, and then correcting the Ni, Sn, and Fe intensity data using the determined correction coefficient. As a correction coefficient, for example, in the standard sample in which a pure Ni plating layer is formed on an iron-based metal plate, the maximum values ​​of the Ni and Fe intensity data can be set to 10, and in the standard sample in which a pure Sn plating layer is formed on a stainless steel plate with strike Ni plating, the maximum value of the Sn intensity data can be set to 10.

[0036] In this measurement, correction factors are set so that each of the above maximum values ​​becomes 10. Then, at depths where the Ni intensity is 1 or greater, it is determined that Ni has been detected; at depths where the Sn intensity is 0.2 or greater, it is determined that Sn has been detected; and at depths where the Fe intensity is 1 or greater, it is determined that Fe has been detected. Therefore, in this measurement, at depths where an intensity of 1 or greater Ni, less than 1 Fe, and less than 0.2 is detected, it is determined that a nickel layer is formed in that region. Similarly, at depths where an intensity of 0.2 or greater Sn, less than 1 Ni, and less than 1 Fe is detected, it is determined that a tin layer is formed in that region. Furthermore, at depths where an intensity of 1 or greater Fe, less than 1 Ni, and less than 0.2 is detected, it is determined that the region consists of Fe (for example, substrate 20). Furthermore, depths where intensities of Ni strength 1 or greater, Sn strength 0.2 or greater, and Fe strength less than 1 are detected are determined to be regions where the nickel-tin alloy layer 40 is formed, and depths where intensities of Ni strength 1 or greater, Fe strength 1 or greater, and Sn strength less than 0.2 are detected are determined to be regions where the iron-nickel alloy layer is formed.

[0037] Here, Figure 4(A) is a graph obtained by GDS measurement of a standard sample in which a pure Ni plating layer was formed on an iron-based metal plate, and Figure 4(B) is a graph obtained by GDS measurement of a standard sample in which a pure Sn plating layer was formed on a stainless steel plate with strike Ni plating. Note that the graphs shown in Figures 4(A) and 4(B) are graphs after correction using the correction coefficients described above. As shown in Figure 4(A), at depth positions where an intensity of Ni strength of 1 or more, Fe strength of less than 1, and Sn strength of less than 0.2 is detected, it is determined that the nickel layer is formed, and at depth positions where an intensity of Ni strength of 1 or more, Fe strength of 1 or more, and Sn strength of less than 0.2 is detected, it is determined that the iron-nickel alloy layer is formed. Also, as shown in Figure 4(B), at depth positions where an intensity of Sn strength of 0.2 or more, Ni strength of less than 1, and Fe strength of less than 1 is detected, it is determined that the tin layer is formed.

[0038] Then, using a high-frequency glow discharge emission spectrometer, the changes in Ni intensity, Sn intensity, and Fe intensity in the surface-treated metal plate 10 for the battery were continuously measured in the depth direction from the outermost surface to the substrate 20, and the etching time (in seconds) in the region where the nickel-tin alloy layer 40 was determined to be formed was measured, and the etching rate R of the pure Ni plating layer was determined. Ni The etching rate R of the nickel-tin alloy layer Ni-Sn The etching rate R of the nickel-tin alloy layer. Ni-Sn The thickness of the nickel-tin alloy layer 40 can be determined from the etching time (in seconds) in the region where the nickel-tin alloy layer 40 is determined to be formed (in μm / second).

[0039] Figure 5(A) is a graph obtained by GDS measurement for the surface-treated metal plate for battery of Example 1, which will be described later. Figure 5(B) is a graph obtained by GDS measurement for the surface-treated metal plate for battery of Example 5, which will be described later. Figure 5(C) is an enlarged graph of the data at the beginning of the measurement in Figure 5(B). As shown in Figure 5(C), the depth positions where intensities showing values ​​of Ni intensity of 1 or more, Sn intensity of 0.2 or more, and Fe intensity of less than 1 are detected are determined to be regions where the nickel-tin alloy layer 40 is formed. The horizontal axis in this region is the etching time (unit: seconds), and the etching rate R of the nickel-tin alloy layer... Ni-Sn (Unit: μm / sec) The thickness of the nickel-tin alloy layer 40 can be determined according to the following formula. Etching time (in seconds) measured by GDS × Etching rate R of the nickel-tin alloy layer Ni-Sn (Unit: μm / sec) = Thickness of nickel-tin alloy layer 40 (Unit: μm)

[0040] In the surface-treated metal plate 10 for batteries of this embodiment, the presence or absence of the nickel-tin alloy layer 40 can be confirmed by performing either the above-mentioned X-ray diffraction (XRD) measurement, or a combination of radiofrequency glow discharge emission surface analysis (GDS) and X-ray diffraction (XRD) measurement. Specifically, if the above-mentioned binary alloy of nickel and tin is found to be present by X-ray diffraction (XRD) measurement, it can be determined that the nickel-tin alloy layer 40 is present.

[0041] In the surface-treated metal plate 10 for batteries of this embodiment, the percentage of Sn (atomic %) on the surface of the nickel-tin alloy layer 40 is preferably 40 atomic % or more. By controlling the percentage of Sn (atomic %) within the above range, the gas generation suppression effect can be further enhanced. From the viewpoint of further enhancing the gas generation suppression effect, the percentage of Sn (atomic %) on the surface of the nickel-tin alloy layer 40 is more preferably 45 atomic % or more, and even more preferably more than 50 atomic %. Furthermore, from the viewpoint of electrolyte resistance, it is sufficient for the nickel-tin alloy layer 40 to be formed on the surface or as a layer below the tin layer 50, so the percentage of Sn (atomic %) on the surface of the nickel-tin alloy layer 40 is not particularly limited and can be 100% or less. Moreover, from the viewpoint of maintaining the percentage of Sn on the surface without changing it even after the anode reaction test described later, it is more preferably 90 atomic % or less, and even more preferably 80 atomic % or less. Furthermore, as long as the proportion of Sn (atomic %) on the surface of the surface on which the nickel-tin alloy layer 40 is formed satisfies the above range, the surface of the surface-treated metal plate 10 for batteries may be either the nickel-tin alloy layer 40 or the tin layer 50. Alternatively, a two-layer structure in which the tin layer 50 is formed on top of the nickel-tin alloy layer 40 is also possible.

[0042] The percentage of Sn (atomic %) on the surface where the nickel-tin alloy layer 40 is formed can be measured by scanning Auger electron spectroscopy (AES). Specifically, first, the surface of the surface treatment metal plate 10 for batteries where the nickel-tin alloy layer 40 is formed is etched to a depth of 10 nm using a scanning Auger electron spectrometer. After etching, the surface is measured using a scanning Auger electron spectrometer, and the peak intensity of 830-860 eV obtained from the measurement is identified as the peak intensity of Ni. Ni The peak intensity of Sn is 415-445 eV. Sn Then, by calculating the proportion of Ni (atomic %) and the proportion of Sn (atomic %) from the obtained peak intensities, the proportion of Sn can be determined. Note that in this case, the peak intensity of Ni is Ni, Sn peak intensity I Sn By dividing the values ​​by the relative sensitivity coefficient (RSF) corresponding to each element, the percentage of Ni (atomic %) and Sn (atomic %) can be calculated. That is, the relative sensitivity coefficients of Ni and Sn are divided by the RSF, respectively. Ni RSF Sn And it can be calculated according to the following formula. Ni ratio (atoms) = (I Ni / RSF Ni ) / (I Ni / RSF Ni +I Sn / RSF Sn ) × 100 Sn percentage (atoms) = (I Sn / RSF Sn ) / (I Ni / RSF Ni +I Sn / RSF Sn ) × 100 The percentage of Ni (atomic %) and Sn (atomic %) on the surface referred to here are the percentages obtained when etching to a depth of 10 nm using the scanning Auger electron spectroscopy analyzer described above.

[0043] The method for controlling the proportion of Sn on the surface of the nickel-tin alloy layer 40 is not particularly limited, but as will be described later, a method of forming a nickel plating layer and a tin plating layer on the substrate 20 in that order and performing a room temperature diffusion treatment or a thermal diffusion treatment is preferred.

[0044] The method for forming the nickel-tin alloy layer 40 is not particularly limited, but examples include forming a nickel plating layer and a tin plating layer on the substrate 20 in that order and causing diffusion at the interface between the nickel plating layer and the tin plating layer at room temperature (room temperature diffusion treatment), or forming a nickel plating layer and a tin plating layer in that order and performing a thermal diffusion treatment by heating. Furthermore, if the substrate 20 is a metal plate (including electrolytic foil) based on Ni, it is also possible to form a tin plating layer on the substrate 20 and form the nickel-tin alloy layer 40 in the same manner as described above.

[0045] In a method of performing a room-temperature diffusion treatment or a thermal diffusion treatment, a preferred method for forming a nickel plating layer is to perform nickel plating on the substrate 20 using a nickel plating bath. As the nickel plating bath, plating baths commonly used in nickel plating, such as a Watt bath, sulfamic acid bath, borofluoride bath, or chloride bath, can be used. For example, for the nickel plating layer, a Watt bath with a bath composition of 200-350 g / L nickel sulfate, 20-60 g / L nickel chloride, and 10-50 g / L boric acid is used, with a pH of 3.0-4.8 (preferably pH 3.6-4.6), a bath temperature of 50-70°C, and a current density of 10-40 A / dm². 2 (Preferably 20-30 A / dm 2 It can be formed under the following conditions.

[0046] Furthermore, in the method of performing a room-temperature diffusion treatment or a thermal diffusion treatment, a preferred method for forming the tin plating layer is to perform tin plating on a nickel-plated substrate 20 using a tin plating bath. The tin plating bath is not particularly limited, and examples include methods using known plating baths such as ferrostan baths, MSA baths, halogen baths, and sulfuric acid baths.

[0047] The processing temperature during the room temperature diffusion treatment is not particularly limited, but is preferably 0°C or higher and less than 50°C. The processing time is not particularly limited, but is preferably 5 hours or more, more preferably 120 hours or more, even more preferably 360 hours or more, and particularly preferably 720 hours or more. By performing the room temperature diffusion treatment, the nickel-tin alloy layer 40 is converted to an alloy phase of Ni-Sn 40-42 , or Ni-Sn 46-48 It may be made to primarily contain one of the following. 40-42 and Ni-Sn 46-48 In order to include both of these, it is preferable to set the processing temperature to 25°C or higher and the processing time to 120 hours or more, and more preferably the processing temperature to 25°C or higher and the processing time to 720 hours or more.

[0048] Furthermore, as a method for performing heat diffusion treatment, the heat treatment conditions when performing heat treatment by box annealing are preferably 50°C to 700°C, more preferably 50°C to 600°C. Also, the soaking time (time after the temperature reaches the target value) when performing heat treatment by box annealing is not particularly limited, but is preferably 0.5 to 8 hours, more preferably 1 to 5 hours, and the total time including heating, soaking, and cooling is preferably in the range of 3 to 80 hours.

[0049] Furthermore, when performing heat treatment by box annealing, the heat treatment conditions may be selected according to the type of alloy phase contained in the nickel-tin alloy layer 40. For example, if the nickel-tin alloy layer 40 contains Ni-Sn as the alloy phase, 40-42 , or Ni-Sn 46-48 When the material mainly contains either of the above, it is preferable to perform heat treatment by box annealing at a relatively low temperature, preferably with a heat treatment temperature of 50°C or higher and less than 100°C, more preferably 50°C or higher and less than 80°C, and a soaking time of preferably 0.5 to 8 hours, more preferably 1 to 5 hours. 40-42 and Ni-Sn 46-48 In order to include both of these, it is preferable to set the heat treatment temperature to 50°C or higher and less than 100°C, and the heat treatment time to 1 to 8 hours, and more preferably the heat treatment temperature to 75°C or higher and less than 100°C, and the heat treatment time to 0.5 to 5 hours.

[0050] If the nickel-tin alloy layer 40 mainly contains Ni3Sn4 as the alloy phase, then the above-mentioned Ni-Sn 40-42 , or Ni-Sn 46-48 It is preferable to perform heat treatment by box annealing under higher temperature conditions compared to cases where one of the above is mainly contained, and the heat treatment temperature by box annealing is preferably 100°C or higher and less than 300°C, more preferably 150°C or higher and less than 300°C, and even more preferably 150°C or higher and less than 250°C, and the soaking time is preferably 1 to 8 hours, more preferably 1 to 5 hours.

[0051] Furthermore, when the nickel-tin alloy layer 40 mainly contains Ni3Sn2 as the alloy phase, it is preferable to perform heat treatment by box annealing under higher temperature conditions compared to the case where Ni3Sn4 is mainly contained as described above. The heat treatment temperature by box annealing is preferably 300°C to 700°C, more preferably 300°C to 600°C, and the soaking time is preferably 1 to 8 hours, more preferably 1 to 5 hours.

[0052] Furthermore, the nickel-tin alloy layer 40 contains Ni3Sn4, Ni3Sn2, and Ni-Sn 40-42 , and Ni-Sn 46-48 The method for incorporating any of the above is not limited to the heat treatment method described above, and continuous annealing may also be used.

[0053] Furthermore, in this embodiment, a configuration may be provided in which a tin layer 50 is further provided on top of the nickel-tin alloy layer 40, as shown in Figure 2, for example, the surface-treated metal plate 10a for batteries. For example, the tin layer 50 can be formed by leaving a portion of the tin plating layer intact when forming the nickel-tin alloy layer 40, for example, by the room-temperature diffusion treatment method or the thermal diffusion treatment method described above. That is, for example, a nickel plating layer and a tin plating layer can be formed on the substrate 20 in that order, and then the tin layer can be formed by the room-temperature diffusion treatment method or the thermal diffusion treatment method at a relatively low temperature.

[0054] The thickness of the tin layer 50 is not particularly limited, but is preferably 2.0 μm or less, more preferably less than 1.0 μm, even more preferably less than 0.5 μm, even more preferably less than 0.3 μm, and particularly preferably less than 0.2 μm. If the thickness of the tin layer 50 is within the above range, it is not expected to have any adverse effect on battery performance. The lower limit of the thickness of the tin layer 50 is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, and particularly preferably 0.1 μm or more. The thickness of the tin layer 50 can be adjusted, for example, by controlling the conditions of room-temperature diffusion treatment or thermal diffusion treatment.

[0055] The thickness of the tin layer 50 can be determined using a high-frequency glow discharge emission spectrometer in a surface-treated metal plate 10 for batteries, where a diffraction peak of Sn has been confirmed by X-ray diffraction (XRD) measurement, and it has been determined that a tin layer is present. Specifically, in the same manner as the measurement of the thickness of the nickel-tin alloy layer 40 described above, the region where the tin layer 50 is formed is identified from the measurement results of the Sn intensity measured in the depth direction from the outermost surface to the substrate 20 using a high-frequency glow discharge emission spectrometer in the surface-treated metal plate 10 for batteries, and the measured Sn intensity and the etching rate R of the pure Sn plating layer are used to determine the region where the tin layer 50 is formed. Sn From this, the thickness of the tin layer 50 can be determined.

[0056] <Nickel layer 30> As shown in Figure 1, the surface-treated metal plate 10 for the battery in this embodiment further comprises a nickel layer 30 as a lower layer of the nickel-tin alloy layer 40. Although Figure 1 illustrates a configuration further comprising a nickel layer 30, the configuration is not limited to this, and a configuration without the nickel layer 30 is also possible.

[0057] The thickness of the nickel layer 30 is preferably 0.05 to 5.00 μm, more preferably 0.15 to 3.00 μm, and even more preferably 0.25 to 3.00 μm. By forming the nickel layer 30 with such a thickness, the surface-treated metal plate 10 for the battery can be made to have improved electrolyte resistance.

[0058] The thickness of the nickel layer 30 can be determined using a high-frequency glow discharge emission spectrometer on a surface-treated metal plate 10 for batteries, where a Ni diffraction peak has been confirmed by X-ray diffraction (XRD) measurement, indicating the presence of a nickel layer. Specifically, in the same manner as the measurement of the thickness of the nickel-tin alloy layer 40 described above, the nickel layer 30 formation region is identified from the Ni intensity measurement results obtained from the depth direction from the outermost surface to the substrate 20 using a high-frequency glow discharge emission spectrometer on the surface-treated metal plate 10 for batteries, and the measured Ni intensity and the etching rate R of the pure Ni plating layer are used. NiFrom this, the thickness of the nickel layer 30 can be determined.

[0059] The method for forming the nickel layer 30 is not particularly limited, but for example, when forming the nickel-tin alloy layer 40 by the room temperature diffusion treatment method or the thermal diffusion treatment method described above, it can be formed by leaving a portion of the nickel plating layer formed on the substrate 20. That is, for example, a nickel plating layer and a tin plating layer can be formed on the substrate 20 in that order, and when performing the room temperature diffusion treatment or thermal diffusion treatment, the presence or absence of the nickel layer 30 and its thickness can be controlled by adjusting the thickness of the nickel plating layer to be formed and the treatment conditions.

[0060] Furthermore, the surface-treated metal plate 10 for batteries in this embodiment may further include an iron-nickel diffusion layer as a lower layer of the nickel layer 30. The iron-nickel diffusion layer can be formed by using an iron-based metal plate as the base material 20, forming a nickel plating layer on the base material 20, and then heat-treating it. The nickel plating conditions for forming the nickel plating layer are not particularly limited, but for example, the same conditions as those for the nickel plating layer formed to form the nickel-tin alloy layer 40 described above may be used. The heat treatment conditions are not particularly limited, but when heat treatment is performed by box annealing, the heat treatment temperature should preferably be between 400°C and 600°C, more preferably between 450°C and 600°C, and the soaking time should preferably be between 0.5 and 8 hours. When heat treatment is performed by continuous annealing, the heat treatment temperature should preferably be between 600°C and 900°C, more preferably between 600°C and 800°C, and the heat treatment time should preferably be between 3 and 120 seconds. Furthermore, when forming an iron-nickel diffusion layer, since the heat treatment conditions for forming the iron-nickel diffusion layer are relatively high, it is desirable to form the iron-nickel diffusion layer beforehand (i.e., after performing the heat treatment for forming the iron-nickel diffusion layer) before forming the nickel-tin alloy layer 40.

[0061] In the surface-treated metal plate 10 for batteries of this embodiment, the amount of tin deposited on the surface on which the nickel-tin alloy layer 40 is formed is preferably 0.05 to 15.0 g / m². 2 And more preferably 0.5~15.0 g / m 2 More preferably 1.0 to 10.0 g / m² 2 Particularly preferred is 1.0 to 7.0 g / m² 2 Furthermore, in the surface-treated metal plate 10 for batteries of this embodiment, when an iron-based metal plate is used as the base material 20, the amount of nickel deposited (Ni deposited) on the surface on which the nickel-tin alloy layer 40 is formed is preferably 2.1 to 65.0 g / m². 2 And more preferably 3.0 to 50.0 g / m² 2 More preferably 3.5 to 25.0 g / m² 2 The amount of tin and nickel deposited can be determined by performing X-ray fluorescence measurement or ICP emission spectroscopy on the surface-treated metal plate 10 for batteries. Note that the above amounts of tin and nickel deposited are the amounts deposited on the surface on which the nickel-tin alloy layer 40 is formed. Therefore, as shown in Figure 1, if the nickel-tin alloy layer 40 is formed on both sides, it is preferable to use the amount deposited on one side rather than the amount deposited on both sides as the above range. Also, as shown in Figures 1 and 2, the total amount deposited when the surface on which the nickel-tin alloy layer 40 is formed has a nickel layer 30 or a tin layer 50 is the same as the above range.

[0062] The surface-treated metal plate 10 for batteries in this embodiment has a base material 20 that is a metal plate based on iron or nickel, and at least one side of the metal plate that forms the base material 20 is provided with a nickel-tin alloy layer 40. This allows for suppression of gas generation and excellent resistance to electrolytes. In particular, when an alkaline electrolyte is used, it exhibits particularly excellent gas generation suppression and electrolyte resistance. Therefore, the surface-treated metal plate 10 for batteries in this embodiment can be preferably used as a current collector or battery container for the positive or negative electrode, taking advantage of these characteristics. In particular, it can be preferably used as a current collector or battery container in alkaline secondary batteries using an alkaline electrolyte, and especially preferably as a current collector or battery container in nickel-zinc batteries. [Examples]

[0063] 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 evaluation methods for each characteristic are as follows.

[0064] <Measurement of nickel and tin deposits> For each example and comparative example, the amount of nickel and tin deposited in the surface-treated metal plates obtained was quantified using a calibration curve method with X-ray fluorescence (XRF) measurement. A Rigaku ZSX100e XRF spectrometer was used. XRF measurement confirmed that it is possible to quantify the metal elements contained in each layer of the surface-treated metal plate—the nickel layer, the nickel-tin alloy layer, and the tin layer—using a calibration curve method.

[0065] <Measurement of nickel layer thickness and nickel-tin alloy layer thickness> For each example and comparative example, the thickness of the nickel layer and the nickel-tin alloy layer of the surface-treated metal plates obtained were measured by high-frequency glow discharge surface spectroscopy (GDS). The GDS measurements were performed under the following conditions. • GDS measurement device: High-frequency glow discharge emission spectrometer (GD-Profiler2, manufactured by Horiba, Ltd.) • Detection function: HDD mode • Anode diameter: 4mm • Excitation mode: Normal • Light source pressure: 600 Pa ·Light source output: 35W • Detection wavelengths: Ni=352nm, Sn=190nm, Fe=371nm

[0066] The specific method for calculating the thickness of each layer was as follows: First, two standard samples were prepared: one with a pure Ni plating layer with a thickness of 0.79 μm formed on a steel plate (cold-rolled low-carbon aluminum-killed steel), and another with a pure Sn plating layer with a thickness of 1.37 μm formed on a stainless steel plate that had been struck with Ni to a thickness of 50 nm or less. Next, using these two standard samples, the intensity of Ni, Sn, and Fe in the thickness direction was measured using a GDS measuring device while etching by sputtering. Figure 4(A) is a graph obtained by performing GDS measurement on the standard sample with the pure Ni plating layer, and Figure 4(B) is a graph obtained by performing GDS measurement on the standard sample with the pure Sn plating layer.

[0067] Next, the Ni, Sn, and Fe intensity data obtained from the measurement of standard samples were corrected so that their maximum values ​​were approximately the same. Specifically, using the two standard samples mentioned above, correction coefficients were determined such that the maximum values ​​of the Ni, Sn, and Fe intensity data were 10, and the intensity data was corrected using these determined correction coefficients.

[0068] Then, using the obtained correction data, Ni was considered detected at depths where the Ni intensity was 1 or greater, Sn was considered detected at depths where the Sn intensity was 0.2 or greater, and Fe was considered detected at depths where the Fe intensity was 1 or greater. Based on the presence or absence of these detections, the boundary points of each layer were determined, and the sputtering time in the region where the nickel layer was formed and the sputtering time in the region where the tin layer was formed were determined. Furthermore, by performing fluorescence X-ray measurements using the above method, the etching rates (in μm / second) of the nickel layer and tin layer were calculated as follows by dividing the thickness (in μm) calculated from the amount of deposit of the nickel layer and tin layer by the sputtering time for the nickel layer and tin layer. Nickel layer etching rate R Ni :0.08177μm / sec Etching rate R of the tin layer Sn :0.3263μm / sec Etching rate R of the nickel-tin alloy layer Ni-Sn (Etching rate of nickel layer R Ni (Same as above): 0.08177 μm / sec

[0069] Next, the Ni, Sn, and Fe strengths at each depth position were measured while etching the surface-treated metal plates obtained in each example and comparative example by sputtering using a GDS measuring device. The measured Ni, Sn, and Fe strengths were then compared with the etching rate R of the nickel layer determined above. Ni , etching rate R of the tin layer Sn , and the etching rate R of the nickel-tin alloy layer Ni-Sn From this, the thickness of the nickel layer 30 and the thickness of the nickel-tin alloy layer 40 were determined. The thickness of the nickel-tin alloy layer 40 was specifically determined as follows. That is, for the depth position where the intensity showing a value of Ni intensity of 1 or more, Sn intensity of 0.2 or more, and Fe intensity of less than 1 was detected, it was judged as the region where the nickel-tin alloy layer 40 was formed. And, from the etching time (unit: seconds) on the horizontal axis in this region and the etching rate R Ni-Sn (unit: μm / second) of the nickel-tin alloy layer, the thickness of the nickel-tin alloy layer 40 was determined according to the following formula. Etching time (unit: seconds) by GDS measurement × etching rate R Ni-Sn (unit: μm / second) of the nickel-tin alloy layer = thickness of the nickel-tin alloy layer 40 (unit: μm)

[0070] Also, for the depth position where the intensity showing a value of Ni intensity of 1 or more, Sn intensity of less than 0.2, and Fe intensity of less than 1 was detected, it was judged as the region where the nickel layer 30 was formed. And, from the etching time (unit: seconds) on the horizontal axis in this region and the etching rate R Ni (unit: μm / second) of the nickel layer, the thickness of the nickel layer 30 was determined according to the following formula. Etching time (unit: seconds) by GDS measurement × etching rate R Ni (unit: μm / second) of the nickel layer = thickness of the nickel layer 30 (unit: μm)

[0071] <X-ray diffraction (XRD) measurement (identification of alloy phases)> For the surface-treated metal plates obtained in each example and comparative example, X-ray diffraction (XRD) measurement was performed to identify the alloy phases contained in the nickel-tin alloy layer 40. In addition, in the X-ray diffraction (XRD) measurement, the presence of the non-alloyed nickel layer and tin layer was also confirmed. As the X-ray diffraction measurement apparatus, SmartLab manufactured by Rigaku Corporation was used, and the surface-treated metal plate obtained was cut into 20 mm × 20 mm and used as the measurement sample. The specific measurement conditions for the X-ray diffraction (XRD) measurement were as follows. (Apparatus configuration) · X-ray source: CuKα • Goniometer radius: 300nm ·Optical system: Concentration method (Induction-side slit system) • Solar slit: 5° • Longitudinal limiting slit: 5mm • Divergent slit: 1 / 2° (Light-receiving slit system) • Scattering slit: 1 / 2° • Solar slit: 5° • Light-receiving slit: 0.3mm • Monochromatic method: Counter monochromator method • Detector: Scintillation counter (Measurement parameters) • Tube voltage-current: 45kV 200mA ·Scanning axis: 2θ / θ • Scanning mode: Continuous • Measurement range: 2θ 30~100° • Scanning speed: 10° / min Step: 0.05°

[0072] The obtained peak intensity values ​​were subjected to background removal using Rigaku's integrated powder X-ray analysis software, PDXL, before data analysis. Here, although the following data have almost the same peak patterns, for example, in Comparative Example 3, which was annealed at 800°C, it was confirmed to be a ternary FeNiSn alloy. Therefore, in this example, the alloy phase was appropriately identified by using data obtained by such GDS measurements in combination. Ni3Sn2:ICDD PDF card 01-072-2561 Fe 2.5 Ni 2.5 Sn:ICDD PDF card 03-065-7279 Furthermore, the presence or absence of nickel and tin layers was determined based on the presence or absence of Ni and Sn diffraction peaks. Ni peaks were determined based on the peaks of the (200) plane appearing at diffraction angles 2θ = 51.5~52.5°, the peaks of the (220) plane appearing at diffraction angles 2θ = 76~77°, and the peaks of the (311) plane appearing at diffraction angles 2θ = 92.5~93.5° (ICDD PDF card 03-065-2865). Sn peaks were determined based on the peaks of the (211) plane appearing at diffraction angles 2θ = 44.7~45.2° (ICDD PDF card 01-072-3240).

[0073] Scanning Auger electron spectroscopy (AES) In some of the surface-treated metal plates obtained in the examples, the percentage of Ni (atomic %) and Sn (atomic %) on the surface where the nickel-tin alloy layer 40 was formed was measured by scanning Auger electron spectroscopy (AES). Specifically, first, the surface of the surface-treated metal plate 10 for batteries, where the nickel-tin alloy layer 40 was formed, was etched to a depth of 10 nm using a scanning Auger electron spectroscopy analyzer, and the surface after etching was measured using a scanning Auger electron spectroscopy analyzer. Then, among the peak intensities obtained from the measurement, the peak intensity of Ni I was determined to be between 830 and 860 eV. Ni The peak intensity of Sn is 415-445 eV. Sn The percentage of Ni (atomic %) and Sn (atomic %) was calculated from the obtained peak intensities. The specific measurement conditions for scanning Auger electron spectroscopy (AES) were as follows. • Acceleration voltage (Probe energy): 10kV ·Irradiation current (Probe current): 1.0×10^-8A • Electronic probe scan mode: Scan • Electron probe diameter: 0 μm • Size: 60 x 48 μm · Stage tilt angle (Probe polar angle to sample normal): 0° · Analyzer analysis mode: CRR (M5) · Measurement start energy (Abscissa start): 30 eV · Measurement end energy (Abscissa end): 1000 eV · Energy step (Abscissa increment): 0.35 eV · Measurement time per measurement point (Collection time (Dwell time)): 20 ms · Number of integrations: 10 times · Measurement time per measurement point (Neutralization active mode): OFF

[0074] In this example, the peak intensity I of Ni Ni , the peak intensity I of Sn Sn were divided by the relative sensitivity factor (RSF) corresponding to each element to calculate the ratio (atomic %) of Ni and the ratio (atomic %) of Sn. More specifically, the relative sensitivity factor of Ni and the relative sensitivity factor of Sn were set as RSF Ni , RSF Sn respectively, and obtained according to the following formula. Ratio of Ni (atomic %) = (I Ni / RSF Ni ) / (I Ni / RSF Ni + I Sn / RSF Sn ) × 100 Ratio of Sn (atomic %) = (I Sn / RSF Sn ) / (I Ni / RSF Ni + I Sn / RSF Sn ) × 100 Here, RSF Ni was 0.469 and RSF Sn was 0.718.

[0075] <Evaluation of electrolyte resistance> For each example and comparative example, the amount of Ni and Sn deposited on the surface-treated metal plates was measured before and after an anodic reaction test using an alkaline solution (30% by weight potassium hydroxide solution). The electrolyte resistance was evaluated by calculating the dissolution rate of the Sn deposited before and after the anodic reaction test. Specifically, assuming the anodic reaction of the negative electrode current collector plate during discharge, where dissolution reactions proceed easily, an anodic reaction test was performed by applying current using an electrochemical measurement method to evaluate the dissolution resistance (electrolyte resistance) in the alkaline solution during discharge. The amount of Sn deposited before and after the anodic reaction test was obtained by the X-ray fluorescence (XRF) measurement described above. Electrolyte resistance was evaluated using either evaluation criterion 1 or evaluation criterion 2 below. If either evaluation criterion 1 or evaluation criterion 2 yields a "◎" or "〇", it can be evaluated that the Sn adhesion state is sufficiently maintained even after the anode reaction test, indicating sufficient electrolyte resistance. Evaluation criterion 1 was performed for each example and comparative example shown in Table 1A, and evaluation criterion 2 was performed for each example and comparative example shown in Table 1B.

[0076] (Evaluation Criterion 1) In evaluation criterion 1, the dissolution rate of the Sn deposit was calculated from the amount of Sn deposited before and after the anodic reaction test obtained from the above measurements, according to the following formula, and evaluated according to the following criteria. Sn dissolution rate (%) = {(Sn amount before anodic reaction) - (Sn amount after anodic reaction) / (Sn amount before anodic reaction)} × 100 If the dissolution rate of the amount of Sn attached before and after the anode reaction test was 10% or less, it was marked as "◎". If the rate of change of the amount of Sn attached before and after the anode reaction test was 40% or less, it was marked as "〇". If the rate of change of the amount of Sn attached before and after the anode reaction test was more than 40%, it was marked as "×".

[0077] (Evaluation Criterion 2) In evaluation criterion 2, the amount of Sn deposited after the anodic reaction test, obtained from the above measurements, was evaluated according to the following criteria. The amount of Sn attached after the anode reaction test was 1.0 g / m². 2 If the above is true, mark it as "○", and the amount of Sn attached after the anode reaction test is 1.0 g / m². 2 If the value was less than the given value, it was marked with "×".

[0078] The anode reaction test was conducted under the following conditions. • Electrochemical measuring instrument: Hokuto Denko Co., Ltd. HZ5000 • Test electrode: Measurement sample (20mm x 20mm) • Opposite electrode: Cu plate ·Reference electrode: Ag / AgCl (KCl saturated) • Electrolyte: 30% by weight potassium hydroxide solution ·Current density: 50mA / cm 2 • Measurement method: Chronopotentiometry • Electrical capacity: 21C / cm² 2

[0079] <Evaluation of gas generation suppression by measuring corrosion current density> The gas generation suppression effect was evaluated for each example and comparative example by measuring the corrosion current density when the surface-treated metal plates obtained were immersed in an alkaline solution. Specifically, surface-treated metal plates were obtained after the anodic reaction using the same anodic reaction test as the electrolyte resistance evaluation method described above. Next, as a test simulating a local cell with deposited Zn, a Zn plate was used as the counter electrode, and the obtained surface-treated metal plates were immersed in an alkaline solution. The corrosion current density was then measured using an electrochemical measurement system to evaluate the gas generation suppression effect. A lower corrosion current density after 30 seconds of immersion in the alkaline solution indicates a higher gas generation suppression effect. Corrosion current density is 20 mA / cm² 2 The following are marked with "◎", and the corrosion current density is 50 mA / cm². 2 The following are marked with "〇", and the corrosion current density is 50 mA / cm². 2 Anything exceeding that value was marked with "×".

[0080] The corrosion current density measurement was performed under the following conditions, and the corrosion current density generated between the test electrode and the counter electrode in a 30 wt% potassium hydroxide solution was measured (unit: mA / cm²). 2 ) was measured. • Measuring device: Hokuto Denko Co., Ltd. HZ5000 • Test electrode: Zn plate (20 x 20 mm, 0.5 mm thick) • Counter electrode: Measurement sample (measurement diameter φ6mm) • Measurement method: Chronocurometry

[0081] <Example 1> First, as the base material 20, a cold-rolled sheet (thickness 110 μm) of low-carbon aluminum-killed steel having the chemical composition shown below was prepared. C: 0.04 wt%, Mn: 0.32 wt%, Si: 0.01 wt%, P: 0.012 wt%, S: 0.014 wt%, remainder: Fe and unavoidable impurities

[0082] Next, the prepared substrate 20 was subjected to electrolytic degreasing and sulfuric acid pickling, and then nickel plating was performed under the following conditions to form nickel plating layers on both sides of the substrate 20. The nickel plating conditions were as follows. The nickel plating processing time was set so that the amount of nickel deposited was as shown in Tables 1A and 1B. (Bath composition: Watt bath) Nickel sulfate hexahydrate: 250g / L Nickel chloride hexahydrate: 45 g / L Boric acid: 30g / L (Plating conditions) Bath temperature: 60℃ pH: 4.0~5.0 Agitation: Air agitation or jet agitation Current density: 10A / dm 2

[0083] Next, the substrate 20 with the nickel plating layer was subjected to tin plating to form tin plating layers on both sides of the substrate 20 with the nickel plating layer. The conditions for tin plating were as follows. The tin plating treatment time was set such that the amount of tin deposited was as shown in Tables 1A and 1B. (Bath composition) Stannous sulfate: 80g / L Phenolsulfonic acid: 60g / L Additive A (ethoxylated α-naphthol): 3g / L Additive B (Ethoxynaphthol sulfonic acid): 3g / L (Plating conditions) pH: 1 or less Bath temperature: 40℃ Current density: 3A / dm 2

[0084] Next, the steel sheet having the nickel-plated layer and tin-plated layer formed above was heat-treated at a temperature of 85°C for 0.5 hours to obtain a surface-treated metal sheet having a nickel-tin alloy layer 40. Then, the above-described measurements were performed on the obtained surface-treated metal sheet. The results are shown in Tables 1A and 1B.

[0085] Furthermore, the percentage of Ni (atomic %) and Sn (atomic %) on the surface of the nickel-tin alloy layer 40 was measured by scanning Auger electron spectroscopy (AES) according to the method described above. The results showed that the percentage of Ni was 18 atomic %, and the percentage of Sn was 82 atomic %, respectively. The results are shown in Table 2. The thickness of the tin layer of the obtained surface-treated metal plate was 0.10 μm.

[0086] As shown in Tables 1A and 1B, in Example 1, the nickel-tin alloy layer 40 contains a nickel-tin alloy as an alloy phase, which yields diffraction peaks in the diffraction angle range 2θ = 40~42° and 2θ = 46~48°. 40-42 and Ni-Sn 46-48 It can be determined that it contains these two substances. The reason is as follows: First, in a standard sample of a pure Ni plating layer formed on an iron-based metal plate as shown in Figure 4(A), the graph obtained by GDS measurement showed that an iron-nickel layer was theoretically possible. However, in the XRD measurement, only peaks for Fe and Ni were confirmed, and no peak for the iron-nickel alloy was confirmed. From this, it was determined that diffusion of Fe and Ni does not occur in room temperature diffusion treatment, and therefore this layer was determined to be a theoretically calculated iron-nickel layer. In other words, although the GDS measurement showed that an iron-nickel layer was formed at the interface between the nickel layer and the iron layer, it was determined that in reality, no iron-nickel layer was formed. On the other hand, Figure 5(A) is a graph obtained by GDS measurement for the surface-treated metal plate for battery of Example 1. From Figure 5(A), the Ni intensity, Sn intensity, and Fe intensity can be confirmed by GDS measurement. Furthermore, in the XRD measurement, in addition to the peaks for pure iron, pure nickel, and pure tin, peaks represented by 2θ = 40~42° and 46~48° were observed. These peaks can be determined to be the peaks for nickel-tin alloy, and thus, Ni-Sn 40-42 and Ni-Sn 46-48 These two were identified as peaks.

[0087] <Example 2> In the same manner as in Example 1, a steel sheet having a nickel plating layer and a tin plating layer was obtained. The obtained steel sheet having the nickel plating layer and tin plating layer was subjected to heat treatment by box annealing in a reducing atmosphere under the conditions of a heat treatment temperature (holding temperature) of 50°C and a soaking time (holding time) of 3 hours, thereby obtaining a surface-treated metal sheet having a nickel-tin alloy layer 40. In the heat treatment by box annealing, the heating time was 1 hour and the cooling time was 1 hour. The treatment times for nickel plating and tin plating were set so that the amount of nickel deposited and the amount of tin deposited were as shown in Tables 1A and 1B. The above measurements were then performed on the obtained surface-treated metal sheet. The results are shown in Tables 1A and 1B. The thickness of the tin layer of the obtained surface-treated metal sheet was 0.16 μm.

[0088] <Examples 3-9> A surface-treated metal sheet having a nickel-tin alloy layer 40 was obtained by performing heat treatment by box annealing in the same manner as in Example 2, except that the heat treatment temperature (holding temperature) by box annealing was changed to the temperature shown in Table 1A. In the heat treatment by box annealing, the heating time was 1 hour and the cooling time was 1 hour. The treatment times for nickel plating and tin plating were set to the amounts of nickel and tin deposited as shown in Table 1A. The above measurements were then performed on the obtained surface-treated metal sheet. The results are shown in Table 1A.

[0089] Furthermore, for Examples 5 and 8, the percentage of Ni (atomic %) and Sn (atomic %) on the surface of the nickel-tin alloy layer 40 was measured by scanning Auger electron spectroscopy (AES) according to the method described above. The results showed that in Example 5, the percentage of Ni was 44 atomic %, and the percentage of Sn was 56 atomic %, while in Example 8, the percentage of Ni was 58 atomic %, and the percentage of Sn was 42 atomic %. The results are shown in Table 2.

[0090] <Examples 10-12> A surface-treated metal sheet having a nickel-tin alloy layer 40 was obtained in the same manner as in Example 5, except that the nickel plating and tin plating times were changed, thereby altering the nickel and tin deposition amounts as shown in Table 1A. The above-described measurements were then performed on the obtained surface-treated metal sheet. The results are shown in Table 1A.

[0091] <Example 13> A surface-treated metal plate having a nickel-tin alloy layer 40 was obtained in the same manner as in Example 5, except that a substrate 20 with through holes having an aperture ratio of 38% and a thickness of 60 μm was used. The nickel plating and tin plating treatment times were set to achieve the nickel and tin deposition amounts shown in Table 1A. The above-described measurements were then performed on the obtained surface-treated metal plate. The results are shown in Table 1A.

[0092] <Example 14> A surface-treated metal plate having a nickel-tin alloy layer 40 was obtained in the same manner as in Example 5, except that an electrolytic foil made of pure iron with a thickness of 6 μm (an electrolytic foil with an iron content of 99.9% by weight or more) was used as the base material 20, and the nickel plating and tin plating times were changed, thereby changing the amount of nickel and tin deposited as shown in Table 1A. The above-described measurements were then performed on the obtained surface-treated metal plate. The results are shown in Table 1A.

[0093] <Example 15> A surface-treated metal plate having a nickel-tin alloy layer 40 was obtained in the same manner as in Example 5, except that an electrolytic foil made of pure nickel with a thickness of 6 μm (an electrolytic foil with an iron content of 99.9% by weight or more) was used as the base material 20, nickel plating was omitted, and the tin plating time was changed, thereby changing the amount of tin deposited as shown in Table 1A. The above-described measurements were then performed on the obtained surface-treated metal plate. The results are shown in Table 1A.

[0094] <Example 16> Using a substrate prepared in the same manner as in Example 1, the processing times for nickel plating and tin plating were set to the amounts of nickel and tin deposited as shown in Table 1B. For nickel and tin deposits, the amount of nickel deposited was measured after forming a nickel plating layer on the substrate, and then the amount of tin deposited was measured after forming a tin plating layer on top of the nickel plating layer. Next, the steel sheet having the nickel-plated layer and tin-plated layer formed above was subjected to room-temperature diffusion treatment by standing at a temperature of 35°C for 720 hours to obtain a surface-treated metal sheet having a nickel-tin alloy layer 40. The above-described measurements were then performed on the obtained surface-treated metal sheet. The results are shown in Table 1B. The thickness of the tin layer in the obtained surface-treated metal sheet was 0.20 μm. In Example 16, the presence of a nickel layer was confirmed by detecting a Ni peak in X-ray diffraction (XRD) measurement, but its thickness could not be measured.

[0095] Furthermore, the percentage of Ni (atomic %) and Sn (atomic %) on the surface of the nickel-tin alloy layer 40 was measured by scanning Auger electron spectroscopy (AES) according to the method described above. The results showed that the percentage of Ni was 4 atomic %, and the percentage of Sn was 96 atomic %, respectively. The results are shown in Table 2.

[0096] <Comparative Example 1> A nickel plate with a thickness of 100 μm was prepared, and in Comparative Example 1, the prepared nickel plate was used as is, and the measurements described above were performed. The results are shown in Table 1A.

[0097] <Comparative Example 2> A surface-treated metal sheet was obtained in the same manner as in Example 1, except that a nickel plating layer was not formed, and only a tin plating layer was formed on the substrate 20. The obtained surface-treated metal sheet was then subjected to the measurements described above. The results are shown in Table 1A.

[0098] <Comparative Example 3> A surface-treated metal sheet was obtained by performing heat treatment by box annealing in the same manner as in Example 2, except that the heat treatment temperature (holding temperature) by box annealing was changed to 800°C. In the heat treatment by box annealing, the heating time was 1 hour and the cooling time was 1 hour. The above-described measurements were then performed on the obtained surface-treated metal sheet. The results are shown in Table 1A.

[0099] <Comparative Example 4> A surface-treated metal sheet was obtained in the same manner as in Example 5, except that the nickel plating and tin plating times were changed, thereby altering the nickel and tin deposition amounts as shown in Table 1. The above-described measurements were then performed on the obtained surface-treated metal sheet. The results are shown in Table 1A.

[0100] <Comparative Example 5> A steel sheet having a nickel plating layer and a tin plating layer was obtained in the same manner as in Example 1, and the above measurements were performed on the obtained steel sheet having the nickel plating layer and the tin plating layer without performing room temperature diffusion treatment or heat treatment (i.e., the above measurements were performed immediately after plating without performing room temperature diffusion treatment or heat treatment). The results are shown in Table 1B.

[0101] [Table 1A]

[0102] [Table 1B]

[0103] [Table 2] Note that "layer plating" in Tables 1A, 1B, and 2 refers to the process of applying nickel plating and tin plating to a substrate in that order.

[0104] As shown in Tables 1A and 1B, surface-treated metal plates, in which a nickel-tin alloy layer is formed on a metal plate based on iron or nickel as a base material, exhibit excellent electrolyte resistance, reduced corrosion current density, and effective suppression of gas generation (Examples 1-16).

[0105] Furthermore, X-ray diffraction (XRD) measurements revealed that in Examples 1, 2, and 16, the alloy phase constituting the nickel-tin alloy layer 40 was Ni-Sn 40-42 and Ni-Sn 46-48 The alloy mainly contains these two elements. Examples 3-6 and 10-15 mainly contain Ni3Sn4 as the alloy phase constituting the nickel-tin alloy layer 40, while Examples 7-9 mainly contain Ni3Sn2 as the alloy phase constituting the nickel-tin alloy layer 40. The X-ray diffraction (XRD) charts of each alloy phase detected in the examples are shown in Figures 3A to 3E. Figure 3A shows Ni-Sn 40-42 and Ni-Sn46-48 Figure 3B is an X-ray diffraction (XRD) chart showing two diffraction peaks (Example 1), Figure 3B is an X-ray diffraction (XRD) chart showing the diffraction peak of Ni3Sn4 (Example 5), and Figure 3C is an X-ray diffraction (XRD) chart showing the diffraction peak of Ni3Sn2 (Example 8). Also, Figures 3D and 3E show Ni-Sn before and after the anode reaction test described above. 40-42 and Ni-Sn 46-48 This is an X-ray diffraction (XRD) chart showing the two diffraction peaks (Example 16).

[0106] Furthermore, X-ray diffraction (XRD) measurements confirmed that Examples 1 and 2 have a tin layer 50 on top of the nickel-tin alloy layer 40 and a nickel layer 30 on the bottom of the nickel-tin alloy layer 40, Examples 3 to 15 have a nickel layer 30 on the bottom of the nickel-tin alloy layer 40, and Example 16 has a tin layer 50 on top of the nickel-tin alloy layer 40.

[0107] More specifically, the alloy phase contained in the nickel-tin alloy layer 40 of each example is Ni-Sn in Examples 1, 2, and 16. 40-42 and Ni-Sn 46-48 It was confirmed that the gas generation suppression effect was superior in the case of products mainly containing these two. Furthermore, as shown in Figures 3D and 3E, Ni-Sn before and after the anode reaction test described above. 40-42 and Ni-Sn 46-48 Based on the confirmation of the two diffraction peaks, it was found that even after the anode reaction test, Ni-Sn 40-42 and Ni-Sn 46-48 We confirmed the presence of two peaks, respectively, and verified that the sample possessed sufficient electrolyte resistance.

[0108] On the other hand, in the cases of Examples 7-9, which mainly contained Ni3Sn2, it was confirmed that they had superior electrolyte resistance. Furthermore, in the cases of Examples 3-6 and 10-15, which mainly contained Ni3Sn4, it was confirmed that both electrolyte resistance and gas generation suppression effect were superior.

[0109] More specifically, in Examples 1, 5, 8, and 16, the percentage of Ni (atomic %) and Sn (atomic %) on the surface of the nickel-tin alloy layer 40 was measured by scanning Auger electron spectroscopy (AES), confirming excellent electrolyte resistance and gas generation suppression effects. In particular, Example 5 showed even greater superiority in both electrolyte resistance and gas generation suppression effects, with surface Ni and Sn percentages (atomic %) of 44 atomic % and 56 atomic %, respectively, on the surface of the nickel-tin alloy layer 40.

[0110] Furthermore, in Comparative Example 3, X-ray diffraction (XRD) measurements revealed that the alloy phase was Fe 2.5 Ni 2.5 Sn3 was detected, confirming the presence of an iron-nickel-tin ternary alloy layer. Furthermore, radiofrequency glow discharge surface spectroscopy (GDS) measurements revealed that the Fe element contained in the substrate 20 had diffused to the surface, and that it lacked a nickel-tin alloy layer (a nickel-tin binary alloy layer). As a result, the corrosion current density was high, and gas generation was significant.

[0111] Figures 5(A) to 5(C) show graphs obtained by GDS measurement for the surface-treated metal plates for batteries of Example 1 and Example 5, respectively. Figure 5(A) is the graph obtained by GDS measurement for the surface-treated metal plate for batteries of Example 1, Figure 5(B) is the graph obtained by GDS measurement for the surface-treated metal plate for batteries of Example 5, and Figure 5(C) is an enlarged graph of the data at the beginning of the measurement in Figure 5(B). [Explanation of Symbols]

[0112] 10,10a... Surface-treated metal sheets for batteries 20...Base material 30… Nickel layer 40…Nickel-tin alloy layer 50...Tin layer

Claims

1. A surface-treated metal plate for an aqueous battery, The base material of the surface-treated metal plate for the aqueous battery is a metal plate based on iron or nickel. The metal plate is provided with a nickel-tin alloy layer on at least one side, The nickel-tin alloy layer has Ni as an alloy phase. ３ Sn ４ It contains, The surface having the nickel-tin alloy layer is characterized in that the proportion of Sn on the surface is 40 atomic percent or more. Surface-treated metal plate for aqueous batteries.

2. A surface-treated metal plate for an aqueous battery, The base material of the surface-treated metal plate for the aqueous battery is a metal plate based on iron or nickel. The metal plate is provided with a nickel-tin alloy layer on at least one side, The nickel-tin alloy layer has Ni as an alloy phase. ３ Sn ２ It contains, The surface having the nickel-tin alloy layer is characterized in that the proportion of Sn on the surface is 40 atomic percent or more. Surface-treated metal plate for aqueous batteries.

3. The surface-treated metal plate for an aqueous battery according to claim 1 or 2, wherein the thickness of the nickel-tin alloy layer, as measured by high-frequency glow discharge surface analysis (GDS), is 0.05 to 5.00 μm.

4. The surface-treated metal plate for an aqueous battery according to claim 1 or 2, further comprising a nickel layer beneath the nickel-tin alloy layer.

5. The amount of nickel deposited on the surface where the nickel-tin alloy layer is formed is 2.1 to 65.0 g / m². ２ A surface-treated metal plate for an aqueous battery according to claim 1 or 2.

6. The amount of tin deposited on the surface where the nickel-tin alloy layer is formed is 0.05 to 15.0 g / m². ２ A surface-treated metal plate for an aqueous battery according to claim 1 or 2.

7. The surface-treated metal plate for an aqueous battery according to claim 1 or 2, wherein the metal plate is made of low-carbon steel or ultra-low-carbon steel.

8. The surface-treated metal plate for an aqueous battery according to claim 1 or 2, wherein the metal plate is an electrolytic foil made of pure iron, an electrolytic foil made of pure nickel, or an electrolytic foil made of a binary alloy of iron and nickel.

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