JP2021163648A - Nickel plating steel foil for nickel-hydrogen secondary battery current collector, nickel-hydrogen secondary battery current collector, and nickel-hydrogen secondary battery - Google Patents
Nickel plating steel foil for nickel-hydrogen secondary battery current collector, nickel-hydrogen secondary battery current collector, and nickel-hydrogen secondary battery Download PDFInfo
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 173
- 239000010959 steel Substances 0.000 title claims abstract description 173
- 239000011888 foil Substances 0.000 title claims abstract description 165
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 29
- 239000001257 hydrogen Substances 0.000 title claims abstract description 28
- 238000007747 plating Methods 0.000 title abstract description 62
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 title description 79
- 229910052759 nickel Inorganic materials 0.000 title description 13
- 230000007547 defect Effects 0.000 claims abstract description 34
- 239000012535 impurity Substances 0.000 claims abstract description 10
- 229910052987 metal hydride Inorganic materials 0.000 claims description 27
- 239000000463 material Substances 0.000 claims description 4
- 239000007773 negative electrode material Substances 0.000 claims description 4
- 239000007774 positive electrode material Substances 0.000 claims description 4
- 238000010828 elution Methods 0.000 abstract description 13
- 229910052751 metal Inorganic materials 0.000 abstract description 11
- 239000002184 metal Substances 0.000 abstract description 11
- 229910052742 iron Inorganic materials 0.000 abstract description 5
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 2
- 229910052710 silicon Inorganic materials 0.000 abstract description 2
- 229910052698 phosphorus Inorganic materials 0.000 abstract 1
- 238000005096 rolling process Methods 0.000 description 43
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 23
- 238000010438 heat treatment Methods 0.000 description 21
- 238000012360 testing method Methods 0.000 description 14
- -1 nickel hydrogen Chemical class 0.000 description 12
- 238000000034 method Methods 0.000 description 10
- 238000004519 manufacturing process Methods 0.000 description 9
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 8
- 239000011149 active material Substances 0.000 description 8
- 229910001416 lithium ion Inorganic materials 0.000 description 8
- 229910021645 metal ion Inorganic materials 0.000 description 8
- 239000003513 alkali Substances 0.000 description 7
- 230000001186 cumulative effect Effects 0.000 description 7
- 239000008151 electrolyte solution Substances 0.000 description 7
- 230000007423 decrease Effects 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 238000010998 test method Methods 0.000 description 6
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 5
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 238000007670 refining Methods 0.000 description 5
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 4
- 238000005097 cold rolling Methods 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 229910052744 lithium Inorganic materials 0.000 description 4
- 229910052758 niobium Inorganic materials 0.000 description 4
- 239000012085 test solution Substances 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 125000004429 atom Chemical group 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 239000007769 metal material Substances 0.000 description 3
- 239000011255 nonaqueous electrolyte Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000005482 strain hardening Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000009864 tensile test Methods 0.000 description 3
- 239000013585 weight reducing agent Substances 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 238000011088 calibration curve Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 239000004745 nonwoven fabric Substances 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 238000001953 recrystallisation Methods 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000037303 wrinkles Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000000295 emission spectrum Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 150000002505 iron Chemical class 0.000 description 1
- YOBAEOGBNPPUQV-UHFFFAOYSA-N iron;trihydrate Chemical compound O.O.O.[Fe].[Fe] YOBAEOGBNPPUQV-UHFFFAOYSA-N 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 description 1
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 1
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 1
- BFDHFSHZJLFAMC-UHFFFAOYSA-L nickel(ii) hydroxide Chemical compound [OH-].[OH-].[Ni+2] BFDHFSHZJLFAMC-UHFFFAOYSA-L 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- GTSHREYGKSITGK-UHFFFAOYSA-N sodium ferrocyanide Chemical compound [Na+].[Na+].[Na+].[Na+].[Fe+2].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] GTSHREYGKSITGK-UHFFFAOYSA-N 0.000 description 1
- 235000012247 sodium ferrocyanide Nutrition 0.000 description 1
- 239000000264 sodium ferrocyanide Substances 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Cell Electrode Carriers And Collectors (AREA)
- Secondary Cells (AREA)
Abstract
Description
本発明は、ニッケル水素二次電池集電体用Ｎｉめっき鋼箔、ニッケル水素二次電池集電体、及びニッケル水素二次電池に関するものである。 The present invention relates to a Ni-plated steel foil for a nickel-metal hydride secondary battery current collector, a nickel-metal hydride secondary battery current collector, and a nickel-metal hydride secondary battery.
近年、パソコンや携帯電話など電子機器の急激な普及に伴い、ニッケル水素二次電池やリチウムイオン二次電池、さらにはリチウムポリマー二次電池など大量の充放電可能な電池が使用されている。特に、ニッケル水素二次電池は高エネルギー密度を有するため、移動体通信、携帯用情報端末用電源として利用されている。また、ニッケル水素二次電池は、エネルギー密度や出力特性は中庸であるが、信頼性や安全性、コスト面で有利であり、近年は、車載用にも実用化されており、その市場が急速に伸びている。それに伴い、小型化、軽量化を、さらに追及するため、機器の中で大きな容積を占める電池に対し、さらなる小型化、軽量化のための性能改善が求められている。 In recent years, with the rapid spread of electronic devices such as personal computers and mobile phones, a large amount of rechargeable and dischargeable batteries such as nickel hydrogen secondary batteries, lithium ion secondary batteries, and lithium polymer secondary batteries have been used. In particular, since the nickel-metal hydride secondary battery has a high energy density, it is used as a power source for mobile communication and portable information terminals. In addition, nickel-metal hydride secondary batteries have moderate energy density and output characteristics, but are advantageous in terms of reliability, safety, and cost. In recent years, they have been put into practical use for in-vehicle use, and the market is rapidly expanding. It is growing to. Along with this, in order to further pursue miniaturization and weight reduction, performance improvement for further miniaturization and weight reduction is required for batteries that occupy a large volume in equipment.
このような二次電池の基本構造は、箔状の金属集電体に可逆的に電気化学反応を起こす物質、いわゆる活物質を塗布した電極、正極及び負極を分離するセパレータ、電解液並びに電池ケースからなっている。ニッケル水素二次電池では、ニッケルフォームを集電体もしくは芯体として用いるのが一般的であるが、ニッケルフォームは複雑な製造工程を経て多孔質体を形成するため、高価である。また、集電体もしくは芯体自体は電池容量に直接寄与しない。そのため、最近の高容量化の要求に応えることを目的に、集電体に安価でかつ薄い金属箔を用いることが検討され始めている。 The basic structure of such a secondary battery is an electrode coated with a substance that reversibly causes an electrochemical reaction in a foil-shaped metal current collector, a so-called active material, a separator for separating positive and negative electrodes, an electrolytic solution, and a battery case. Consists of. In a nickel-metal hydride secondary battery, nickel foam is generally used as a current collector or a core body, but nickel foam is expensive because it forms a porous body through a complicated manufacturing process. Further, the current collector or the core itself does not directly contribute to the battery capacity. Therefore, in order to meet the recent demand for higher capacity, it has begun to be considered to use an inexpensive and thin metal foil for the current collector.
上記にあげる箔状の金属集電体として、鉄系の箔が従来提案されている。鉄は、銅に比較すると電気抵抗が大きいが、近年の電池構造の工夫とともに、電池の用途、要求特性の多様化から、電気抵抗が必ずしも問題とはならなくなってきている。 Iron-based foils have been conventionally proposed as the foil-shaped metal current collectors mentioned above. Iron has a higher electrical resistance than copper, but due to the recent ingenuity of the battery structure and the diversification of battery applications and required characteristics, electrical resistance has not necessarily become a problem.
負極集電体に鉄箔を用いるものとしては、特許文献１に、厚さ３５ミクロン以下の電解鉄箔を、リチウム二次電池の負極の集電体に用いることが提案されている。また、防錆性の観点から、Ｎｉめっきされた電解鉄箔を用いることも提案されている。 As a method of using an iron foil for the negative electrode current collector, Patent Document 1 proposes using an electrolytic iron foil having a thickness of 35 microns or less for the negative electrode current collector of a lithium secondary battery. It has also been proposed to use Ni-plated electrolytic iron foil from the viewpoint of rust prevention.
特許文献２には、鉄箔又はＮｉめっきを施した鉄箔の表面に三二酸化鉄を形成してなる金属箔を、リチウム二次電池等の非水電解質二次電池の負極集電体に用いることが提案されている。しかし、この鉄系金属箔は過放電時のＦｅ溶出が避けられないとともに、負極電位での副反応が起き易く、結果として、電池の効率や寿命を阻害し易い。 In Patent Document 2, a metal foil formed by forming iron sesquioxide on the surface of an iron foil or an iron foil plated with Ni is used as a negative electrode current collector of a non-aqueous electrolyte secondary battery such as a lithium secondary battery. Has been proposed. However, this iron-based metal foil inevitably elutes Fe at the time of over-discharging, and a side reaction at the negative electrode potential is likely to occur, and as a result, the efficiency and life of the battery are likely to be impaired.
特許文献３、４には、リチウムイオン二次電池等の非水系電解液二次電池の負極集電体に用いることができる鋼箔が提案されている。これらの鋼箔は、薄くて強度があり、軽量で経済的であり、防錆性、過放電時の耐金属イオン溶出性、負極電位での安定性に優れた負極集電体用高強度鋼箔であることが記載されている。 Patent Documents 3 and 4 propose steel foils that can be used as a negative electrode current collector of a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. These steel foils are thin, strong, lightweight and economical, and have excellent rust resistance, metal ion elution resistance during overdischarge, and stability at the negative electrode potential. High-strength steel for negative electrode current collectors. It is stated that it is a foil.
以上の特許文献に記載されているように、鋼箔は、薄くて強度があり、軽量で経済的であり、防錆性、過放電時の耐金属イオン溶出性、負極電位での安定性を有しており、リチウムイオン二次電池の負極集電体用として優れていることがわかっている。
しかし、これらの特許文献で提案されている鉄箔、鋼箔はいずれも、リチウムイオン二次電池用であり、ニッケル水素二次電池の集電体用ではない。
As described in the above patent documents, the steel foil is thin and strong, lightweight and economical, and has rust resistance, metal ion elution resistance during over-discharge, and stability at the negative electrode potential. It has and is known to be excellent for the negative electrode current collector of lithium ion secondary batteries.
However, the iron foil and the steel foil proposed in these patent documents are all for lithium ion secondary batteries, not for the current collector of nickel hydrogen secondary batteries.
特許文献３、４に記載されている鋼箔は、薄くて強度があり、防錆性、過放電時の耐金属溶出性、負極電位での安定性に優れているので、これらの鋼箔をニッケル水素二次電池の集電体として用いることが企図される。
しかし、特許文献３，４に記載の鋼箔をニッケル水素二次電池の集電体に用いると、ニッケル水素二次電池の理論容量（Ａｈ／ｋｇ）を遥かに下回る容量しか得られないことが分かっている。この理由は、リチウムイオン二次電池の電解液とニッケル水素二次電池の電解液とが異なっているためであると考えられる。リチウムイオン二次電池の電解液は、リチウム電池の特性上、非水系電解液が用いられている。一方、ニッケル水素二次電池では、通常、アルカリ性水溶液が用いられている。そのため、リチウムイオン二次電池集電体用の鋼箔では問題にはならなかった、アルカリ性水溶液環境下での集電体からの金属イオンの溶出が、ニッケル水素二次電池での電池容量の低下に関係していると考えられる。
The steel foils described in Patent Documents 3 and 4 are thin and strong, and are excellent in rust resistance, metal elution resistance at the time of over-discharge, and stability at a negative electrode potential. It is intended to be used as a current collector for nickel-metal hydride secondary batteries.
However, when the steel foil described in Patent Documents 3 and 4 is used as a current collector of a nickel-metal hydride secondary battery, a capacity far lower than the theoretical capacity (Ah / kg) of the nickel-metal hydride secondary battery can be obtained. I know. It is considered that the reason for this is that the electrolytic solution of the lithium ion secondary battery and the electrolytic solution of the nickel hydrogen secondary battery are different. As the electrolytic solution of the lithium ion secondary battery, a non-aqueous electrolyte solution is used due to the characteristics of the lithium battery. On the other hand, in a nickel-metal hydride secondary battery, an alkaline aqueous solution is usually used. Therefore, elution of metal ions from the current collector in an alkaline aqueous solution environment, which was not a problem with the steel foil for the lithium-ion secondary battery current collector, reduces the battery capacity of the nickel-metal hydride secondary battery. It is thought that it is related to.
また、鋼箔を集電体として用いた電極を捲回するときなどに鋼箔が破断することを防止するために、より高い伸び性が求められている。 Further, in order to prevent the steel foil from breaking when the electrode using the steel foil as a current collector is wound, higher extensibility is required.
本発明は、薄くて強度があり、伸び性、耐金属イオン溶出性に優れるニッケル水素二次電池集電体用Ｎｉめっき鋼箔、当該Ｎｉめっき鋼箔を備えるニッケル水素二次電池集電体、及び当該Ｎｉめっき鋼箔を備えるニッケル水素二次電池の提供を目的とする。 INDUSTRIAL APPLICABILITY The present invention relates to a Ni-plated steel foil for a nickel-hydrogen secondary battery current collector, which is thin and strong, and has excellent extensibility and metal ion elution resistance, and a nickel-hydrogen secondary battery current collector provided with the Ni-plated steel foil. An object of the present invention is to provide a nickel hydrogen secondary battery provided with the Ni-plated steel foil.
本願発明者らは、上記ニッケル水素二次電池の容量低下の原因が、集電体として用いる鋼箔の金属成分、特にＦｅ成分が電解液に溶出して、正極上で酸化されることにあることを知見した。この知見を基に、このＦｅ成分の溶出を抑制するためのＮｉめっき層を備えた鋼箔に特定の条件で熱処理を施すことで、Ｆｅの溶出防止性能を維持しつつ、優れた強度及び伸びを鋼箔に付与することで本発明を完成させた。 The inventors of the present application have found that the cause of the decrease in the capacity of the nickel-metal hydride secondary battery is that the metal component of the steel foil used as the current collector, particularly the Fe component, elutes into the electrolytic solution and is oxidized on the positive electrode. I found that. Based on this finding, by heat-treating a steel foil provided with a Ni plating layer for suppressing the elution of Fe components under specific conditions, excellent strength and elongation can be maintained while maintaining Fe elution prevention performance. Was applied to the steel foil to complete the present invention.
上記目的を達成する本発明の要旨は、以下のとおりである。 The gist of the present invention that achieves the above object is as follows.
（１）質量％で、
Ｃ：０．０００１〜０．０２００％、
Ｓｉ：０．０００１〜０．０２００％、
Ｍｎ：０．００５〜０．３００％、
Ｐ：０．００１〜０．０２０％、
Ｓ：０．０００１〜０．０１００％、
Ａｌ：０．０００５〜０．１０００％、
Ｎ：０．０００１〜０．００４０％、
を含み、
Ｔｉ：０．８００％以下、
Ｎｂ：０．０５０％以下、の１種又は２種を含み、
そして残部がＦｅ及び不純物からなり、Ｎｉめっき層を両面に有するＮｉめっき鋼箔であって、
前記Ｎｉめっき鋼箔の第１面及び第２面Ｎｉめっき層の厚みが、それぞれ、０．１５μｍ以上であり、
前記Ｎｉめっき鋼箔の厚みが、５μｍ〜５０μｍであり、
伸びが３％以上であり、
引張強度が４００ＭＰａ以上１０００ＭＰａ以下であり、
表面欠陥面積率が前記Ｎｉめっき鋼箔の前記第１面及び前記第２面ともに５．００％以下であることを特徴とするニッケル水素二次電池集電体用Ｎｉめっき鋼箔。
（２）前記Ｎｉめっき鋼箔の厚みが、１０μｍ〜３０μｍである前記（１）に記載のニッケル水素二次電池集電体用Ｎｉめっき鋼箔。
（３）前記Ｎｉめっき鋼箔の前記第１面及び前記第２面の前記Ｎｉめっき層の厚みが、それぞれ、０．２０μｍ以上１．５０μｍ以下である前記（１）又は（２）に記載のニッケル水素二次電池集電体用Ｎｉめっき鋼箔。
（４）前記（１）〜（３）のいずれか１つに記載のニッケル水素二次電池集電体用Ｎｉめっき鋼箔からなるニッケル水素二次電池集電体。
（５）正極集電体上に、正極活物質層、セパレータ、負極活物質層及び負極集電体が順次積層されてなるニッケル水素二次電池であって、前記正極集電体及び前記負極集電体の少なくとも一方が、前記（４）に記載のニッケル水素二次電池集電体である、ニッケル水素二次電池。
(1) By mass%
C: 0.0001 to 0.0200%,
Si: 0.0001 to 0.0200%,
Mn: 0.005 to 0.300%,
P: 0.001 to 0.020%,
S: 0.0001 to 0.0100%,
Al: 0.0005 to 0.1000%,
N: 0.0001 to 0.0040%,
Including
Ti: 0.800% or less,
Nb: Includes one or two types of 0.050% or less,
The balance is a Ni-plated steel foil composed of Fe and impurities and having a Ni-plated layer on both sides.
The thickness of the first surface and the second surface Ni plating layer of the Ni-plated steel foil is 0.15 μm or more, respectively.
The thickness of the Ni-plated steel foil is 5 μm to 50 μm.
Growth is 3% or more,
The tensile strength is 400 MPa or more and 1000 MPa or less.
A Ni-plated steel foil for a nickel-metal hydride secondary battery current collector, wherein the surface defect area ratio is 5.00% or less on both the first surface and the second surface of the Ni-plated steel foil.
(2) The Ni-plated steel foil for a nickel-metal hydride secondary battery current collector according to (1) above, wherein the thickness of the Ni-plated steel foil is 10 μm to 30 μm.
(3) The above-mentioned (1) or (2), wherein the thickness of the Ni-plated layer on the first surface and the second surface of the Ni-plated steel foil is 0.20 μm or more and 1.50 μm or less, respectively. Ni-plated steel foil for nickel-metal hydride secondary battery current collector.
(4) The nickel-metal hydride secondary battery current collector made of Ni-plated steel foil for the nickel-metal hydride secondary battery current collector according to any one of (1) to (3) above.
(5) A nickel-hydrogen secondary battery in which a positive electrode active material layer, a separator, a negative electrode active material layer, and a negative electrode current collector are sequentially laminated on a positive electrode current collector, and the positive electrode current collector and the negative electrode collector. A nickel-hydrogen secondary battery in which at least one of the electric bodies is the nickel-hydrogen secondary battery current collector according to the above (4).
本発明の上記態様によれば、薄くて強度があり、伸び性、耐金属イオン溶出性に優れるニッケル水素二次電池集電体用Ｎｉめっき鋼箔、当該Ｎｉめっき鋼箔を備えるニッケル水素二次電池集電体、及び当該Ｎｉめっき鋼箔を備えるニッケル水素二次電池を提供することができる。本発明のニッケル水素二次電池集電体用Ｎｉめっき鋼箔は、ニッケル水素二次電池の正極集電体及び負極集電体のいずれにも好適に使用することができる。 According to the above aspect of the present invention, a nickel hydrogen secondary battery Ni-plated steel foil for a current collector, which is thin and strong, and has excellent extensibility and metal ion elution resistance, and a nickel-hydrogen secondary provided with the Ni-plated steel foil. A battery current collector and a nickel-hydrogen secondary battery provided with the Ni-plated steel foil can be provided. The Ni-plated steel foil for a nickel-metal hydride secondary battery current collector of the present invention can be suitably used for both a positive electrode current collector and a negative electrode current collector of a nickel-metal hydride secondary battery.
（Ｎｉめっき鋼箔）
本発明の実施形態に係るニッケル水素二次電池集電体用Ｎｉめっき鋼箔（以下、「Ｎｉめっき鋼箔」ということがある。）は、下記の鋼成分組成からなり（％は質量％）、Ｎｉめっき鋼箔の両面（第１面及び第２面）のＮｉめっき層の厚みが、それぞれ、０．１５μｍ以上であり、Ｎｉめっき鋼箔の厚みが、５μｍ〜５０μｍであり、伸びが３％以上であり、引張強度が４００ＭＰａ以上１０００ＭＰａ以下であり、表面欠陥面積率がＮｉめっき鋼箔の第１面及び第２面ともに５．００％以下である。なお、本発明の実施形態に係るＮｉめっき鋼箔は、鋼箔及びめっき層を備える。
(Ni plated steel foil)
The Ni-plated steel foil for a nickel-hydrogen secondary battery current collector (hereinafter, may be referred to as “Ni-plated steel foil”) according to the embodiment of the present invention has the following steel composition (% is mass%). , The thickness of the Ni plating layer on both sides (first surface and second surface) of the Ni-plated steel foil is 0.15 μm or more, respectively, the thickness of the Ni-plated steel foil is 5 μm to 50 μm, and the elongation is 3. % Or more, the tensile strength is 400 MPa or more and 1000 MPa or less, and the surface defect area ratio is 5.00% or less on both the first surface and the second surface of the Ni-plated steel foil. The Ni-plated steel foil according to the embodiment of the present invention includes a steel foil and a plating layer.
本発明の実施形態に係るＮｉめっき鋼箔は、特に、表面欠陥面積率がＮｉめっき鋼箔の第１面及び第２面ともに５．００％以下である。前述したように、リチウムイオン二次電池集電体用の鋼箔をニッケル水素二次電池の集電体に用いると、過放電時以外では特に問題にはならなかった集電体成分の金属イオン溶出に起因する電池容量の低下が問題になる。
本願発明者らは、研究の結果この電池容量の低下が、Ｎｉめっき鋼箔の表面欠陥により、鋼箔の金属成分、特にＦｅ成分が、アルカリ性水溶液に溶出することに起因することを見出した。
The Ni-plated steel foil according to the embodiment of the present invention has a surface defect area ratio of 5.00% or less on both the first surface and the second surface of the Ni-plated steel foil. As described above, when the steel foil for the lithium ion secondary battery current collector is used for the current collector of the nickel hydrogen secondary battery, the metal ion of the current collector component does not cause any particular problem except during over-discharge. The decrease in battery capacity due to elution becomes a problem.
As a result of research, the inventors of the present application have found that this decrease in battery capacity is caused by the metal component of the steel foil, particularly the Fe component, being eluted into an alkaline aqueous solution due to a surface defect of the Ni-plated steel foil.
Ｎｉめっき鋼箔の表面欠陥としては、Ｎｉめっきされた鋼板（薄板）を、圧延してＮｉめっき鋼箔にする際、圧延ロールとの接触や、被圧延材の変形により導入される、Ｎｉめっき層のクラックや疵、剥がれなどの不良が挙げられる。このＮｉめっき層の不良部から、鋼箔の金属成分のＦｅが、電解質のアルカリ性水溶液に溶出して、ニッケル水素二次電池の電池容量が、急速に低下してしまうことが分かった。 As a surface defect of Ni-plated steel foil, when a Ni-plated steel sheet (thin plate) is rolled into a Ni-plated steel foil, Ni plating is introduced due to contact with a rolling roll or deformation of the material to be rolled. Defects such as layer cracks, flaws, and peeling can be mentioned. From the defective portion of the Ni plating layer, it was found that Fe, which is a metal component of the steel foil, elutes into the alkaline aqueous solution of the electrolyte, and the battery capacity of the nickel-metal hydride secondary battery rapidly decreases.
本願発明者らは、Ｎｉめっきされた鋼板（薄板）を、圧延してＮｉめっき鋼箔にする際の箔圧延工程を制御することで、このＮｉめっき層の不良を、劇的に低減させることができることを見出した。また、熱処理条件を制御することで、Ｎｉめっき層中のＮｉの拡散を抑制しつつ、優れた強度及び伸びを付与できることを見出した。本発明の実施形態に係るＮｉめっき鋼箔の表面欠陥面積率は、第１面及び第２面ともに５．００％以下である。表面欠陥面積率が５．００％を超えると、電解液へのＦｅイオンの溶出量が大きくなり、理論容量の半分以下の電池容量しか得られない。Ｎｉめっき鋼箔の表面に欠陥がないことが好ましいので、Ｎｉめっき鋼箔の欠陥面積率の下限は０％である。 The inventors of the present application dramatically reduce defects in the Ni-plated layer by controlling the foil rolling process when rolling a Ni-plated steel sheet (thin sheet) into a Ni-plated steel foil. I found that I could do it. It was also found that by controlling the heat treatment conditions, it is possible to impart excellent strength and elongation while suppressing the diffusion of Ni in the Ni plating layer. The surface defect area ratio of the Ni-plated steel foil according to the embodiment of the present invention is 5.00% or less on both the first surface and the second surface. When the surface defect area ratio exceeds 5.00%, the amount of Fe ions eluted into the electrolytic solution becomes large, and the battery capacity is less than half of the theoretical capacity. Since it is preferable that there are no defects on the surface of the Ni-plated steel foil, the lower limit of the defect area ratio of the Ni-plated steel foil is 0%.
Ｎｉめっき鋼板の表面欠陥面積率は、一般的にフェロキシル試験によって評価される。本発明の実施形態に係るＮｉめっき鋼箔の表面欠陥面積率は、下記試験方法に基づいて得られた試験片の第１面及び第２面（表裏の両面）の表面欠陥の写真から計算される。 The surface defect area ratio of a Ni-plated steel sheet is generally evaluated by a ferroxyl test. The surface defect area ratio of the Ni-plated steel foil according to the embodiment of the present invention is calculated from photographs of surface defects on the first surface and the second surface (both front and back surfaces) of the test piece obtained based on the following test method. NS.
具体的な操作としては、まず、純水に、フェロシアン化ナトリウム（ヘキサシアノ鉄(II)酸カリウム三水和物）１０ｇ／Ｌ、フェリシアン化カリウム（ヘキサシアノ鉄（ＩＩＩ）酸カリウム三水和物）１０ｇ／Ｌ、及び塩化ナトリウム５ｇ／Ｌを溶解させたフェロキシル試験溶液を用意する。この試験溶液に、第１面及び第２面にＮｉめっき層を有する５０ｍｍ角のＮｉめっき鋼箔試験片を３分間浸漬する。この試験片を試験溶液から取り出し、水洗し、６５℃で、５分間乾燥する。青色斑点が現れた試験片の第１面及び第２面を写真に撮り、コンピュータに取り込み、画像解析ソフトを用いて二値化処理して、第１面及び第２面の表面欠陥面積率を数値化する。一例としてＩｍａｇｅＪ（画像解析ソフト）の２つの閾値による二値化処理機能を用いて前述する青色斑点を識別する方法を記載する。はじめにコンピュータに取り込んだ写真を８ｂｉｔでグレースケール化する。なお８ｂｉｔで保存されたグレースケール画像では、光度が０のときは黒、最大値２５５のときは白を表す。光度の閾値として０と２１５とを設定すると青色斑点を精度よく識別できることが判明している。そこで、これらの光度が０〜２１５の範囲が色変わりするよう画像を処理し、青色斑点を識別する。その後、解析機能を用いて青色斑点部の面積率を算出する。なお二値化処理はＩｍａｇｅＪ以外の画像解析ソフトを使用してもよい。 As a specific operation, first, sodium ferrocyanide (potassium ferricyanide trihydrate) 10 g / L and potassium ferricyanide (potassium ferricyanide trihydrate) 10 g are added to pure water. Prepare a ferroxyl test solution in which / L and 5 g / L of sodium chloride are dissolved. A 50 mm square Ni-plated steel foil test piece having a Ni-plated layer on the first and second surfaces is immersed in this test solution for 3 minutes. The test piece is removed from the test solution, washed with water and dried at 65 ° C. for 5 minutes. The first and second surfaces of the test piece in which the blue spots appeared were photographed, imported into a computer, and binarized using image analysis software to determine the surface defect area ratio of the first and second surfaces. Quantify. As an example, the above-mentioned method for identifying blue spots by using the binarization processing function based on two threshold values of ImageJ (image analysis software) will be described. First, the photos captured on the computer are grayscaled with 8 bits. In the grayscale image saved in 8 bits, when the luminous intensity is 0, it represents black, and when the maximum value is 255, it represents white. It has been found that blue spots can be accurately identified by setting 0 and 215 as the luminosity thresholds. Therefore, the image is processed so that the luminosity changes in the range of 0 to 215, and the blue spots are identified. After that, the area ratio of the blue spots is calculated using the analysis function. Image analysis software other than ImageJ may be used for the binarization process.
本発明の実施形態に係るＮｉめっき鋼箔の成分は、
Ｃ：０．０００１〜０．０２００％、
Ｓｉ：０．０００１〜０．０２００％、
Ｍｎ：０．００５〜０．３００％、
Ｐ：０．００１〜０．０２０％、
Ｓ：０．０００１〜０．０１００％、
Ａｌ：０．０００５〜０．１０００％、
Ｎ：０．０００１〜０．００４０％、
を含み、
Ｔｉ：０．８００％以下、
Ｎｂ：０．０５０％以下、の１種又は２種
を含み、
残部がＦｅ及び不純物である。
The components of the Ni-plated steel foil according to the embodiment of the present invention are
C: 0.0001 to 0.0200%,
Si: 0.0001 to 0.0200%,
Mn: 0.005 to 0.300%,
P: 0.001 to 0.020%,
S: 0.0001 to 0.0100%,
Al: 0.0005 to 0.1000%,
N: 0.0001 to 0.0040%,
Including
Ti: 0.800% or less,
Nb: Includes one or two types of 0.050% or less,
The balance is Fe and impurities.
まず、成分組成の限定理由を説明する。なお、本明細書中において、「〜」を用いて表される数値範囲は、「〜」の前後に記載される数値を下限値及び上限値として含む範囲を意味する。「未満」、「超」と示す数値には、その値が数値範囲に含まれない。成分の％は質量％を意味する。 First, the reason for limiting the component composition will be described. In the present specification, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value. Numerical values indicated as "less than" and "greater than" do not include the values in the numerical range. The% of the component means mass%.
（Ｃ：０．０００１〜０．０２００％）
Ｃは、鋼の強度を高める元素であり、Ｃ含有量の増加とともに加工硬化が起こりやすくなる。Ｃ含有量の増加とともに冷間圧延時の変形抵抗が大きくなると、圧延ロールでの高い加圧が必要になるため、Ｎｉめっきされた鋼板（薄板）を圧延してＮｉめっき鋼箔にする際に導入されるＮｉめっき層の欠陥が増えてしまう。さらに、過剰にＣを含有させると鋼の電気抵抗が悪化する場合があるので、Ｃ含有量の上限を０．０２００％とする。Ｃ含有量の下限は、特に規定されないが、現行の精錬技術における限界が０．０００１％程度であるので、これを下限とした。Ｃ含有量は、より好ましくは０．００１０％〜０．０１００％である。
(C: 0.0001 to 0.0200%)
C is an element that enhances the strength of steel, and work hardening is likely to occur as the C content increases. When the deformation resistance during cold rolling increases as the C content increases, high pressurization with a rolling roll is required. Therefore, when rolling a Ni-plated steel sheet (thin sheet) into a Ni-plated steel foil, The number of defects in the introduced Ni plating layer increases. Further, if C is excessively contained, the electric resistance of the steel may be deteriorated, so the upper limit of the C content is set to 0.0200%. The lower limit of the C content is not particularly specified, but since the limit in the current refining technique is about 0.0001%, this is set as the lower limit. The C content is more preferably 0.0010% to 0.0100%.
（Ｓｉ：０．０００１〜０．０２００％）
Ｓｉは、鋼の強度を高める元素であるが、過剰に含有させると鋼の電気抵抗が悪化する場合があるので、Ｓｉ含有量の上限を０．０２００％とする。Ｓｉ含有量を０．０００１％未満にすると、精練コストが多大となるので、Ｓｉ含有量の下限は０．０００１％とする。Ｓｉ含有量は、より好ましくは０．００１０％〜０．００８０％である。
(Si: 0.0001 to 0.0200%)
Si is an element that enhances the strength of steel, but if it is contained in excess, the electrical resistance of the steel may deteriorate. Therefore, the upper limit of the Si content is set to 0.0200%. If the Si content is less than 0.0001%, the refining cost becomes large, so the lower limit of the Si content is set to 0.0001%. The Si content is more preferably 0.0010% to 0.0080%.
（Ｍｎ：０．００５〜０．３００％）
Ｍｎは、鋼の強度を高める元素であるが、過剰に含有させると鋼の電気抵抗が悪化する場合があるので、Ｍｎ含有量の上限を０．３００％とする。Ｍｎ含有量を０．００５％未満にすると、精練コストが多大となるとともに、鋼が軟質化しすぎて圧延性が低下してしまう場合があるため、Ｍｎ含有量の下限は０．００５％とする。Ｍｎ含有量は、より好ましくは０．０５０％〜０．２００％である。
(Mn: 0.005 to 0.300%)
Mn is an element that enhances the strength of steel, but if it is contained in excess, the electrical resistance of the steel may deteriorate. Therefore, the upper limit of the Mn content is set to 0.300%. If the Mn content is less than 0.005%, the refining cost becomes high and the steel may become too soft and the rollability may deteriorate. Therefore, the lower limit of the Mn content is set to 0.005%. .. The Mn content is more preferably 0.050% to 0.200%.
（Ｐ：０．００１〜０．０２０％）
Ｐは、鋼の強度を高める元素であるが、過剰に含有させると鋼の電気抵抗が悪化する場合があるので、Ｐ含有量の上限を０．０２０％とする。Ｐ含有量を０．００１％未満にすると、精練コストが多大となる場合があるので、Ｐ含有量の下限は０．００１％とする。Ｐ含有量は、より好ましくは０．００１％〜０．０１０％である。
(P: 0.001 to 0.020%)
P is an element that increases the strength of steel, but if it is contained in excess, the electrical resistance of the steel may deteriorate. Therefore, the upper limit of the P content is set to 0.020%. If the P content is less than 0.001%, the refining cost may increase. Therefore, the lower limit of the P content is set to 0.001%. The P content is more preferably 0.001% to 0.010%.
（Ｓ：０．０００１〜０．０１００％）
Ｓは、鋼の熱間加工性及び耐食性を低下させる元素であるから、少ないほど好ましい。さらに、本実施形態に係る鋼箔のような薄い鋼箔の場合、Ｓが多いと、Ｓの存在に起因する介在物によって電気抵抗が悪化したり、また、鋼の強度が低下したりする場合があるので、Ｓ含有量の上限は０．０１００％とする。Ｓ含有量を０．０００１％未満にすると、精練コストが多大となる場合があるので、Ｓ含有量の下限は０．０００１％とする。Ｓ含有量は、より好ましくは０．００１０％〜０．００８０％である。
(S: 0.0001 to 0.0100%)
Since S is an element that lowers the hot workability and corrosion resistance of steel, the smaller the amount, the more preferable. Further, in the case of a thin steel foil such as the steel foil according to the present embodiment, if there is a large amount of S, the electrical resistance may be deteriorated due to inclusions caused by the presence of S, or the strength of the steel may be lowered. Therefore, the upper limit of the S content is 0.0100%. If the S content is less than 0.0001%, the refining cost may increase. Therefore, the lower limit of the S content is set to 0.0001%. The S content is more preferably 0.0010% to 0.0080%.
（Ａｌ：０．０００５〜０．１０００％）
Ａｌは、鋼の脱酸元素として０．０００５％以上を含有させる。過剰に含有させると、電気抵抗が悪化し、また、製造コストの増大を招く場合があるので、Ａｌ含有量の上限は０．１０００％とする。Ａｌ含有量は、より好ましくは０．０１００％〜０．０５００％である。
(Al: 0.0005 to 0.1000%)
Al contains 0.0005% or more as a deoxidizing element of steel. If it is contained in an excessive amount, the electric resistance deteriorates and the manufacturing cost may increase. Therefore, the upper limit of the Al content is set to 0.1000%. The Al content is more preferably 0.0100% to 0.0500%.
（Ｎ：０．０００１〜０．００４０％）
Ｎは、鋼の熱間加工性及び加工性を低下させる元素であるから、少ないほど好ましく、Ｎ含有量の上限は０．００４０％とする。Ｎ含有量を０．０００１％未満にすると、コストが多大となる場合があるので、Ｎ含有量の下限は０．０００１％とする。Ｎ含有量は、より好ましくは０．００１０％〜０．００３０％である。
(N: 0.0001 to 0.0040%)
Since N is an element that lowers the hot workability and workability of steel, the smaller the amount, the more preferable, and the upper limit of the N content is 0.0040%. If the N content is less than 0.0001%, the cost may become large, so the lower limit of the N content is set to 0.0001%. The N content is more preferably 0.0010% to 0.0030%.
（Ｔｉ：０．８００％以下、Ｎｂ：０．０５０％以下の１種又は２種）
本発明の実施形態に係るＮｉめっき鋼箔の鋼箔は、Ｔｉ及びＮｂは、鋼中のＣ及びＮを炭化物及び窒化物として固定して、鋼の加工性を向上させることができるので、これらから選択される１種を単独で、または２種を複合して含有してもよい。ただし、いずれの元素も過剰に含有すると、製造コストの増大、及び電気抵抗の悪化を招く場合がある。好ましい含有量範囲は、Ｔｉ：０．０１０〜０．８００％、Ｎｂ：０．００５〜０．０５０％である。さらに好ましい含有量範囲は、Ｔｉ：０．０１０〜０．１００％、Ｎｂ：０．００５〜０．０４０％である。
(Ti: 0.800% or less, Nb: 0.050% or less, 1 type or 2 types)
In the steel foil of the Ni-plated steel foil according to the embodiment of the present invention, Ti and Nb can fix C and N in the steel as carbides and nitrides to improve the workability of the steel. One selected from the above may be contained alone or in combination of two. However, if any of the elements is contained in excess, the manufacturing cost may increase and the electric resistance may deteriorate. The preferred content range is Ti: 0.010 to 0.800% and Nb: 0.005 to 0.050%. A more preferable content range is Ti: 0.010 to 0.100% and Nb: 0.005 to 0.040%.
（不純物）
本明細書で用いる用語「不純物」は、原料由来の不純物元素、Ｎｉめっき鋼板の製造中に混入する元素及び意図的に添加された元素であって、本発明の特性を阻害しない範囲の元素のことを意味する。本発明の実施形態に係る鋼箔では、本発明の特性を阻害しない範囲で不純物の混入が許容される。
(impurities)
As used herein, the term "impurity" refers to an impurity element derived from a raw material, an element mixed in during the production of a Ni-plated steel sheet, and an element intentionally added, which does not impair the characteristics of the present invention. Means that. In the steel foil according to the embodiment of the present invention, impurities are allowed to be mixed as long as the characteristics of the present invention are not impaired.
本発明の実施形態に係る鋼箔は、さらに、付加的に、Ｆｅの一部に代えて、Ｂ、Ｃｕ、Ｎｉ、Ｓｎ、Ｃｒ等の元素を、本発明の実施形態に係る鋼箔の特性を損なわない範囲で含有してもよい。 In addition, the steel foil according to the embodiment of the present invention contains elements such as B, Cu, Ni, Sn, and Cr instead of a part of Fe, which are the characteristics of the steel foil according to the embodiment of the present invention. May be contained within a range that does not impair.
上述したＮｉめっき鋼箔の成分は、一般的な分析方法によって測定すればよい。成分の測定箇所は、中央部とする。ここで、中央部とは、Ｎｉめっき鋼箔の端部から１ｃｍの部分を除いた任意の場所である。例えば、ＩＣＰ−ＡＥＳ（Ｉｎｄｕｃｔｉｖｅｌｙ Ｃｏｕｐｌｅｄ Ｐｌａｓｍａ−Ａｔｏｍｉｃ Ｅｍｉｓｓｉｏｎ Ｓｐｅｃｔｒｏｍｅｔｒｙ）を用いて測定すればよい。なお、ＣおよびＳは燃焼−赤外線吸収法を用い、Ｎは不活性ガス融解−熱伝導度法を用いて測定すればよい。表面のＮｉめっき層を機械研削により除去してから化学組成の分析を行えばよい。 The components of the Ni-plated steel foil described above may be measured by a general analytical method. The measurement point of the component is the central part. Here, the central portion is an arbitrary location excluding a portion 1 cm from the end portion of the Ni-plated steel foil. For example, measurement may be performed using ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrum). C and S may be measured by using the combustion-infrared absorption method, and N may be measured by using the inert gas melting-thermal conductivity method. The Ni plating layer on the surface may be removed by mechanical grinding, and then the chemical composition may be analyzed.
本発明の実施形態に係るＮｉめっき鋼箔は、鋼箔の第1面及び第２面に、Ｎｉめっき層を有する。ここで、第１面は、Ｎｉめっき鋼箔の一方の面をいい、第２面は、Ｎｉめっき鋼箔のもう一方の面をいう。
鋼箔上の第１面及び第２面に付着したＮｉめっき層の厚みは、それぞれ、０．１５μｍ以上である。Ｎｉめっき層の厚みが厚いほど、鋼箔からの金属溶出性が改善されるが、コストは増加する。各面のＮｉめっき層の厚みが２．００μｍを超えても、顕著な性能向上は認められないので、コスト対効果の観点から、Ｎｉめっき層の厚みの実質的な上限は２．００μｍである。Ｎｉめっき層のより好ましい厚みは、０．２０μｍ以上１．５０μｍ以下である。
The Ni-plated steel foil according to the embodiment of the present invention has a Ni-plated layer on the first surface and the second surface of the steel foil. Here, the first surface refers to one surface of the Ni-plated steel foil, and the second surface refers to the other surface of the Ni-plated steel foil.
The thickness of the Ni plating layer adhering to the first surface and the second surface on the steel foil is 0.15 μm or more, respectively. The thicker the Ni plating layer, the better the metal elution property from the steel foil, but the higher the cost. Even if the thickness of the Ni plating layer on each surface exceeds 2.00 μm, no significant performance improvement is observed. Therefore, from the viewpoint of cost effectiveness, the practical upper limit of the thickness of the Ni plating layer is 2.00 μm. .. The more preferable thickness of the Ni plating layer is 0.20 μm or more and 1.50 μm or less.
箔圧延前の鋼板の第１面及び第２面にＮｉめっきを施し（圧延前めっき）、このＮｉめっき鋼板を焼鈍し、Ｆｅ−Ｎｉ拡散層（Ｆｅ−Ｎｉ合金層ともいう）を形成させた後、箔圧延する。Ｎｉめっき層を有する鋼板の箔圧延には細心の注意を要する。例えば、箔圧延の際のＮｉめっき層の伸びが鋼板の伸びに比較して小さい場合、Ｎｉめっき層にクラックなどの欠陥が発生し、この欠陥が箔強度の低下を引き起こす場合がある。 Ni plating was applied to the first and second surfaces of the steel sheet before foil rolling (pre-rolling plating), and this Ni-plated steel sheet was annealed to form an Fe—Ni diffusion layer (also referred to as Fe—Ni alloy layer). After that, the foil is rolled. Great care must be taken when rolling a steel sheet having a Ni plating layer. For example, when the elongation of the Ni plating layer during foil rolling is smaller than the elongation of the steel sheet, defects such as cracks may occur in the Ni plating layer, and these defects may cause a decrease in foil strength.
箔強度を低下させないＮｉめっきとしては、軟質Ｎｉめっきが特に好適である。具体的には、鋼板上に付着させた、不純物以外は含有しない純Ｎｉめっきを、３００℃以上の熱処理を行い、これによって、めっき層のひずみを解放したＮｉめっきを本発明の実施形態に係るＮｉめっき鋼箔における軟質Ｎｉめっきとしてもよい。また、Ｎｉめっきは、箔圧延中に導入されたＮｉめっき層の欠陥の補修を目的に、箔圧延後に追加で実施してもよい。 As the Ni plating that does not reduce the foil strength, soft Ni plating is particularly suitable. Specifically, according to the embodiment of the present invention, pure Ni plating adhering to a steel sheet containing only impurities is heat-treated at 300 ° C. or higher to release the strain of the plating layer. It may be soft Ni plating in Ni plating steel foil. Further, the Ni plating may be additionally performed after the foil rolling for the purpose of repairing defects in the Ni plating layer introduced during the foil rolling.
なお、Ｎｉめっき鋼鈑のめっき厚は、ＪＩＳ Ｈ８５０１−１９９９に規定する試験方法に基づいて測定される。すなわち、製造上はめっき電流値によって制御されるが、直接的には、箔圧延前の鋼板の第１面及び第２面にＮｉめっきを施し（圧延前めっき）、このＮｉめっき鋼板を焼鈍する前に、ＩＣＰ等の化学分析を用いて、Ｎｉめっきの付着量（ｇ／ｍ２）を測定する。Ｎｉめっき目付量毎に予め検量線を作成しておき、Ｎｉの蛍光Ｘ線強度からＮｉめっき厚を算出する。ただし、Ｎｉめっき鋼鈑を焼鈍した後は、内部に拡散したＮｉの検出強度が低くなるため、同一の目付量であっても、蛍光Ｘ線強度は低めに検知される。そのため、Ｎｉめっき鋼鈑を焼鈍した後の検量線を新たに作成する必要がある。 The plating thickness of the Ni-plated steel plate is measured based on the test method specified in JIS H8501-1999. That is, although it is controlled by the plating current value in manufacturing, Ni plating is directly applied to the first and second surfaces of the steel sheet before foil rolling (pre-rolling plating), and the Ni-plated steel sheet is annealed. Before, the adhesion amount (g / m 2 ) of Ni plating is measured by using a chemical analysis such as ICP. A calibration curve is prepared in advance for each Ni plating grain amount, and the Ni plating thickness is calculated from the fluorescence X-ray intensity of Ni. However, after the Ni-plated steel plate is annealed, the detection intensity of Ni diffused inside becomes low, so that the fluorescent X-ray intensity is detected low even if the amount of the grain is the same. Therefore, it is necessary to create a new calibration curve after annealing the Ni-plated steel plate.
さらに、Ｎｉめっき鋼箔のめっき厚は、グロー放電発行分光分析法（ＧＤＳ）によって測定する。具体的には、ＧＤＳによって測定されるＮｉ原子の深さ方向のプロファイルにおいて、Ｎｉ原子の含有比率が最大値の１／２となる深さをＮｉめっき厚とする。ＧＤＳによって測定されるＦｅ原子の含有量が９０質量％以上となる領域を鋼箔とする。また、Ｎｉめっき層と鋼箔との間に存在する領域をＦｅ−Ｎｉ合金層とする。ここで、深さの基準には、シリコン単結晶のスパッタリング時間とスパッタリング速度との積に換算して得られた厚さを用いる。なお、Ｎｉめっき鋼箔のＮｉめっき層のＮｉ含有量の最大値は９０質量％以上である。このＮｉの最大含有量は、ＧＤＳで各元素の含有量を測定することで得られる。 Further, the plating thickness of the Ni-plated steel foil is measured by glow discharge emission spectroscopy (GDS). Specifically, in the profile in the depth direction of Ni atoms measured by GDS, the depth at which the content ratio of Ni atoms is 1/2 of the maximum value is defined as the Ni plating thickness. The region where the Fe atom content measured by GDS is 90% by mass or more is defined as a steel foil. Further, the region existing between the Ni plating layer and the steel foil is defined as the Fe—Ni alloy layer. Here, as the reference of the depth, the thickness obtained by converting the product of the sputtering time and the sputtering rate of the silicon single crystal is used. The maximum value of the Ni content of the Ni-plated layer of the Ni-plated steel foil is 90% by mass or more. The maximum content of Ni can be obtained by measuring the content of each element with GDS.
本発明の実施形態に係るＮｉめっき鋼箔の厚みは、Ｎｉめっき層を含めて５μｍ〜５０μｍである。これは、本発明のような機械的強度が十分に高いＮｉめっき鋼箔を用いて電池を小型化及び軽量化していくうえでは、薄い集電体、すなわち薄い鋼箔が望まれるからである。小型化及び軽量化の観点からは、鋼箔はより薄い方が好ましく、下限を特に限定する必要はない。しかしながら、コスト又は厚さの均一性を考えると、５μｍ以上がよい。Ｎｉめっき鋼箔の厚みは、好ましくは、１０μｍ〜３０μｍである。 The thickness of the Ni-plated steel foil according to the embodiment of the present invention is 5 μm to 50 μm including the Ni-plated layer. This is because a thin current collector, that is, a thin steel foil is desired in order to reduce the size and weight of the battery by using the Ni-plated steel foil having sufficiently high mechanical strength as in the present invention. From the viewpoint of miniaturization and weight reduction, the steel foil is preferably thinner, and the lower limit does not need to be particularly limited. However, considering the cost or thickness uniformity, 5 μm or more is preferable. The thickness of the Ni-plated steel foil is preferably 10 μm to 30 μm.
本発明の実施形態に係るＮｉめっき鋼箔の伸びは、３％以上である。より好ましくは、４％以上であり、さらに好ましくは５％以上である。破断伸びが３％以上であれば、Ｎｉめっき鋼箔を捲回する際に破断することを十分に防止することができる。なお、ここで、伸びとは、破断伸びを意味する。伸びは、ＪＩＳ Ｚ２２４１−２０１１に規定する金属材料引張試験方法に準拠する試験方法に基づいて測定される。試験片の形状は１３Ｂ号、引張方向は圧延方向とする。試験速度は１ｍｍ／ｍｉｎとする。 The elongation of the Ni-plated steel foil according to the embodiment of the present invention is 3% or more. More preferably, it is 4% or more, and further preferably 5% or more. When the breaking elongation is 3% or more, it is possible to sufficiently prevent the Ni-plated steel foil from breaking when it is wound. Here, the elongation means the elongation at break. Elongation is measured based on a test method conforming to the metal material tensile test method specified in JIS Z2241-2011. The shape of the test piece is No. 13B, and the tensile direction is the rolling direction. The test speed is 1 mm / min.
本発明の実施形態に係るＮｉめっき鋼箔の引張強度は、４００ＭＰａ以上１０００ＭＰａ以下である。なお、引張強度は、常温での測定値である。伸びが３％以上の場合において、引張強度が４００ＭＰａ未満となると、集電体に活物質層を塗工する際の取り扱いによる皺や折れの発生や、充放電に伴う活物質の膨張収縮により、鋼箔が変形したり活物質が剥がれたりする問題が起きる可能性がある。なお、鋼箔の引張強度は、ＪＩＳ Ｚ２２４１−２０１１に規定する金属材料引張試験方法に準拠する試験方法に基づいて測定される。試験片の形状は１３Ｂ号、引張方向は圧延方向とする。試験速度は１ｍｍ／ｍｉｎとする。 The tensile strength of the Ni-plated steel foil according to the embodiment of the present invention is 400 MPa or more and 1000 MPa or less. The tensile strength is a measured value at room temperature. When the elongation is 3% or more and the tensile strength is less than 400 MPa, wrinkles and breaks occur due to handling when the active material layer is applied to the current collector, and the active material expands and contracts due to charging and discharging. Problems such as deformation of the steel foil and peeling of the active material may occur. The tensile strength of the steel foil is measured based on a test method based on the metal material tensile test method specified in JIS Z2241-2011. The shape of the test piece is No. 13B, and the tensile direction is the rolling direction. The test speed is 1 mm / min.
鋼箔の皺や折れ、変形及び活物質の剥離を防止する観点からは、特に、引張強度の上限を限定する必要はない。しかしながら、取り扱いの容易性、及び工業的な圧延による加工硬化によって強度を得る際の安定性を考慮すると、伸びが３％以上の場合では、引張強度１０００ＭＰａが鋼箔の引張強度の実質的な上限となる。 From the viewpoint of preventing wrinkles, breakage, deformation and peeling of the active material of the steel foil, it is not necessary to limit the upper limit of the tensile strength. However, considering the ease of handling and the stability when obtaining strength by work hardening by industrial rolling, when the elongation is 3% or more, the tensile strength of 1000 MPa is a substantial upper limit of the tensile strength of the steel foil. It becomes.
（Ｎｉめっき鋼箔の製造方法）
本発明の実施形態に係るＮｉめっき鋼箔の製造方法は、以下の通りである。まず、通常の薄板製法に従って、前述した所定の成分組成の薄板（鋼板）を製造する。その後、箔圧延前の鋼板の第１面及び第２面にＮｉめっきを施す。このＮｉめっき鋼板を、焼鈍し、Ｆｅ−Ｎｉ拡散層（Ｆｅ−Ｎｉ合金層ともいう）を形成させた後、冷間圧延（箔圧延）によって、５μｍ〜５０μｍ厚のＮｉめっき鋼箔とする。冷間圧延によって生じる加工硬化を利用して、６００Ｍｐａ超１２００ＭＰａ以下の高強度のＮｉめっき鋼箔を製造する。
(Manufacturing method of Ni-plated steel foil)
The method for producing a Ni-plated steel foil according to an embodiment of the present invention is as follows. First, a thin plate (steel plate) having the above-mentioned predetermined component composition is produced according to a normal thin plate manufacturing method. After that, Ni plating is applied to the first surface and the second surface of the steel sheet before foil rolling. This Ni-plated steel sheet is annealed to form a Fe—Ni diffusion layer (also referred to as an Fe—Ni alloy layer), and then cold-rolled (foil rolling) to obtain a Ni-plated steel foil having a thickness of 5 μm to 50 μm. Utilizing the work hardening caused by cold rolling, a high-strength Ni-plated steel foil of more than 600 MPa and 1200 MPa or less is produced.
箔圧延の際の累積圧下率は７０％以上とする。ここで、累積圧下率とは、最初の圧延スタンドの入口板厚に対する累積圧下量（最初のパス前の入口板厚と最終パス後の出口板厚との差）の百分率である。累積圧下率が７０％未満であると、十分な箔強度が発現しない。箔圧延の際の累積圧下率は、好ましくは８０％以上である。累積圧下率の上限は、特に限定されない。しかしながら通常の圧延能力では、９８％程度が達成できる累積圧下率の限界である。また、各パスでの圧延によるめっき不良を低減させるために、圧延の各パスの圧下率は、５〜４０％の範囲とすることが好ましい。 The cumulative rolling reduction rate during foil rolling is 70% or more. Here, the cumulative rolling reduction ratio is a percentage of the cumulative rolling reduction amount (the difference between the inlet plate thickness before the first pass and the outlet plate thickness after the final pass) with respect to the inlet plate thickness of the first rolling stand. If the cumulative reduction rate is less than 70%, sufficient foil strength will not be developed. The cumulative rolling reduction rate during foil rolling is preferably 80% or more. The upper limit of the cumulative reduction rate is not particularly limited. However, with normal rolling capacity, it is the limit of the cumulative rolling reduction rate that can be achieved at about 98%. Further, in order to reduce plating defects due to rolling in each pass, the reduction rate of each rolling pass is preferably in the range of 5 to 40%.
また、各パスの単位圧延荷重（ｋＮ／ｍｍ）を適正域にコントロールする。単位圧延荷重とは、圧延ロールから被加工材にかかる荷重を被加工材の板幅で除したものである。好ましい単位圧延荷重は、０．５〜１．２ｋＮ／ｍｍである。０．５ｋＮ／ｍｍ未満であると、圧延に伴う加工発熱が少なく、Ｎｉめっき層の柔軟性が低下するため、Ｎｉめっき層にクラックが生じ、表面欠陥面積率が高くなる。また、１．２ｋＮ／ｍｍを超えても、加工発熱が多くなりすぎるため、Ｎｉめっき層が圧延ロールにピックアップされてしまうため（圧延ロールにＮｉが付着）、表面欠陥面積率は高くなる。 In addition, the unit rolling load (kN / mm) of each pass is controlled in an appropriate range. The unit rolling load is the load applied to the work material from the rolling roll divided by the plate width of the work material. A preferable unit rolling load is 0.5 to 1.2 kN / mm. If it is less than 0.5 kN / mm, the processing heat generated by rolling is small and the flexibility of the Ni plating layer is lowered, so that cracks occur in the Ni plating layer and the surface defect area ratio becomes high. Further, even if it exceeds 1.2 kN / mm, the processing heat generation becomes too large, and the Ni plating layer is picked up by the rolling roll (Ni adheres to the rolling roll), so that the surface defect area ratio becomes high.
冷間圧延後のＮｉめっき鋼箔に対し、熱処理を行う。熱処理は７００℃〜８５０℃の温度域で３秒〜３０秒の条件で行う。熱処理を行うことで、伸びを３％以上としつつ、引張強度を４００ＭＰａ以上１０００ＭＰａ以下の範囲に制御する。 Heat treatment is performed on the Ni-plated steel foil after cold rolling. The heat treatment is performed in a temperature range of 700 ° C. to 850 ° C. under the condition of 3 seconds to 30 seconds. By performing the heat treatment, the tensile strength is controlled in the range of 400 MPa or more and 1000 MPa or less while the elongation is set to 3% or more.
熱処理の温度が７００℃未満の場合、Ｎｉめっき鋼箔の再結晶が十分進まず、伸びが３％以上とならない。そのため、熱処理の温度は７００℃以上とする。熱処理の温度が８５０℃超の場合、Ｎｉめっき層のＮｉが鋼箔中に拡散するので、表面欠陥率が５％超となる。そのため、熱処理の温度は８５０℃以下とする。 If the heat treatment temperature is less than 700 ° C., the recrystallization of the Ni-plated steel foil does not proceed sufficiently and the elongation does not exceed 3%. Therefore, the temperature of the heat treatment is 700 ° C. or higher. When the heat treatment temperature exceeds 850 ° C., Ni in the Ni plating layer diffuses into the steel foil, so that the surface defect rate becomes more than 5%. Therefore, the heat treatment temperature is set to 850 ° C. or lower.
熱処理の処理時間は３秒未満であると、Ｎｉめっき鋼箔の再結晶が十分進まず、伸びが3％以上とならない。そのため、熱処理の処理時間は、３秒以上である。熱処理の処理時間が３０秒超の場合、Ｎｉめっき層のＮｉが鋼箔中に拡散するので、表面欠陥率が５％超となる。そのため、熱処理の処理時間は、３０秒以下である。 If the heat treatment treatment time is less than 3 seconds, the recrystallization of the Ni-plated steel foil does not proceed sufficiently and the elongation does not exceed 3%. Therefore, the heat treatment treatment time is 3 seconds or more. When the heat treatment treatment time exceeds 30 seconds, Ni in the Ni plating layer diffuses into the steel foil, so that the surface defect rate becomes more than 5%. Therefore, the heat treatment treatment time is 30 seconds or less.
また、本発明の実施形態に係るＮｉめっき鋼箔を、ニッケル水素二次電池正極集電体又は負極集電体として用いることで、電池容量が低下しにくい、つまり電池寿命の長いニッケル水素電池を得ることができる。具体的には、一般的なニッケル水素二次電池は、正極集電体上に、正極活物質層、セパレータ、負極活物質層及び負極集電体が順次積層されてなるが、本発明の実施形態に係るＮｉめっき鋼箔からなるニッケル水素二次電池集電体を上述の正極集電体及び上述の負極集電体の少なくとも一方に用いる。本発明の実施形態に係るニッケル水素二次電池集電体は、Ｎｉめっき鋼箔をそのまま用いてもよいし、活物質層との接触面積を改善するために、表面加工を施してもよい。
Ｎｉめっき鋼箔は正極集電体及び負極集電体のどちらにも好適に使用できるが、耐金属イオン溶出性に優れるという観点から、特に正極集電体として好適に使用できる。
Further, by using the Ni-plated steel foil according to the embodiment of the present invention as a positive electrode current collector or a negative electrode current collector of a nickel hydrogen secondary battery, a nickel hydrogen battery whose battery capacity is unlikely to decrease, that is, a nickel hydrogen battery having a long battery life can be obtained. Obtainable. Specifically, in a general nickel-hydrogen secondary battery, a positive electrode active material layer, a separator, a negative electrode active material layer, and a negative electrode current collector are sequentially laminated on a positive electrode current collector. A nickel-hydrogen secondary battery current collector made of Ni-plated steel foil according to the embodiment is used for at least one of the above-mentioned positive electrode current collector and the above-mentioned negative electrode current collector. The nickel-metal hydride secondary battery current collector according to the embodiment of the present invention may use Ni-plated steel foil as it is, or may be surface-processed in order to improve the contact area with the active material layer.
The Ni-plated steel foil can be suitably used for both a positive electrode current collector and a negative electrode current collector, but can be particularly preferably used as a positive electrode current collector from the viewpoint of excellent metal ion elution resistance.
この本発明の実施形態に係るニッケル水素電池において、本発明の実施形態に係るＮｉめっき鋼箔以外の各構成部材は、公知のものを使用することができる。
Ｎｉめっき鋼箔以外の正極集電体及び負極集電体としては、例えば、ニッケル箔が挙げられる。
正極活物質層に用いられる活物質としては、例えば、水酸化ニッケルが挙げられる。
負極活物質層に用いられる活物質としては、例えば、水素吸蔵合金が挙げられる。
セパレータとしては、例えば、ポリオレフィン不織布、ポリアミド不織布が挙げられる。
これらの構成部材の他に、公知の外装容器、集電リード、電解液、導電助剤、バインダーを構成部材として使用することができる。
In the nickel-metal hydride battery according to the embodiment of the present invention, known components other than the Ni-plated steel foil according to the embodiment of the present invention can be used.
Examples of the positive electrode current collector and the negative electrode current collector other than the Ni-plated steel foil include nickel foil.
Examples of the active material used for the positive electrode active material layer include nickel hydroxide.
Examples of the active material used for the negative electrode active material layer include hydrogen storage alloys.
Examples of the separator include polyolefin non-woven fabric and polyamide non-woven fabric.
In addition to these constituent members, known outer containers, current collector leads, electrolytic solutions, conductive auxiliaries, and binders can be used as the constituent members.
次に、本発明の実施例について説明するが、実施例の条件は、本発明の実施可能性及び効果を確認するために採用した一条件例であり、本発明は、この一条件例に限定されるものではない。本発明は、本発明の要旨を逸脱せず、本発明の目的を達成する限りにおいて、種々の条件を採用し得るものである。 Next, examples of the present invention will be described. The conditions of the examples are one condition example adopted for confirming the feasibility and effect of the present invention, and the present invention is limited to this one condition example. It is not something that is done. In the present invention, various conditions can be adopted as long as the gist of the present invention is not deviated and the object of the present invention is achieved.
〔試験用Ｎｉめっき鋼箔の準備〕
下記の成分を有するスラブＡを溶製した。残部はＦｅおよび不純物であり、単位は質量％である。
[Preparation of test Ni-plated steel foil]
Slab A having the following components was melted. The balance is Fe and impurities, and the unit is mass%.
表１に示す成分組成のスラブＡから、通常の薄板製造方法により熱間圧延、冷間圧延を行い、板厚０．１５ｍｍの薄板を得た。 From the slab A having the component composition shown in Table 1, hot rolling and cold rolling were carried out by a usual thin plate manufacturing method to obtain a thin plate having a plate thickness of 0.15 mm.
〔Ｎｉめっきを施す操作〕
Ｎｉめっきでは、硫酸ニッケル：３２０ｇ／Ｌ、塩化ニッケル：７０ｇ／Ｌ、ほう酸：４０ｇ／Ｌを含むめっき浴を用い、浴温度：６５℃、電解電流：２０Ａ／ｄｍ２の条件にて、通板速度を変えて、めっき厚み３．９〜８．５μｍのＮｉめっき層を鋼板の両面に形成した。次いで、５％Ｈ２（残部Ｎ２）雰囲気で保持温度８２０℃かつ保持時間４０秒で連続焼鈍処理を行った。
[Operation to apply Ni plating]
In Ni plating, a plating bath containing nickel sulfate: 320 g / L, nickel chloride: 70 g / L, and boric acid: 40 g / L is used, and the plate is passed under the conditions of bath temperature: 65 ° C. and electrolytic current: 20 A / dm 2. At different speeds, Ni plating layers with a plating thickness of 3.9 to 8.5 μm were formed on both sides of the steel plate. Next, continuous annealing treatment was performed in a 5% H 2 (remaining N 2 ) atmosphere at a holding temperature of 820 ° C. and a holding time of 40 seconds.
〔箔圧延の操作〕
表２に示すように、各パス単位圧延荷重の最小／最大（ｋＮ／ｍｍ）に設定して、箔圧延操作を行った。上記操作により、鋼箔番号１及び８の鋼箔を得た。
[Foil rolling operation]
As shown in Table 2, the foil rolling operation was performed by setting the minimum / maximum (kN / mm) of the rolling load for each pass. By the above operation, steel foils of steel foil numbers 1 and 8 were obtained.
〔熱処理の操作〕
箔圧延の操作後、表２に示す熱処理条件で、熱処理を行った。なお、表２中の熱処理温度及び熱処理時間の欄の「−」は、熱処理を行っていないことを示す。上記操作により、鋼箔番号２〜７及び１０の鋼箔を得た。
[Heat treatment operation]
After the foil rolling operation, the heat treatment was performed under the heat treatment conditions shown in Table 2. In addition, "-" in the column of the heat treatment temperature and the heat treatment time in Table 2 indicates that the heat treatment was not performed. By the above operation, steel foils having steel foil numbers 2 to 7 and 10 were obtained.
〔Ｎｉめっき鋼箔の厚みの測定〕
得られたＮｉめっき鋼箔の厚みを、電気マイクロメーターによって測定した。結果を表２に示す。
[Measurement of Ni-plated steel foil thickness]
The thickness of the obtained Ni-plated steel foil was measured with an electric micrometer. The results are shown in Table 2.
〔めっき厚の測定〕
得られた鋼箔のめっき厚みを、前記のグロー放電発行分光分析法によって測定した。Ｎｉめっき層の厚みが０．１５μｍ以上を合格とし、それ以外を不合格とした。結果を表３に示す。
[Measurement of plating thickness]
The plating thickness of the obtained steel foil was measured by the above-mentioned glow discharge issuance spectroscopic analysis method. A Ni plating layer having a thickness of 0.15 μm or more was accepted, and the others were rejected. The results are shown in Table 3.
〔引張強度及び伸びの測定〕
得られたＮｉめっき鋼箔の引張強度及び破断伸びを、ＪＩＳ Ｚ２２４１−２０１１に規定する金属材料引張試験方法に準拠する試験方法に基づいて測定した。引張強度が４００ＭＰａ以上１０００ＭＰａ以下を合格とし、それ以外を不合格とした。また破断伸びが３％以上を合格とし、それ以外を不合格とした。結果を表３に示す。
[Measurement of tensile strength and elongation]
The tensile strength and elongation at break of the obtained Ni-plated steel foil were measured based on a test method based on the metal material tensile test method specified in JIS Z2241-2011. Tensile strength of 400 MPa or more and 1000 MPa or less was accepted, and other than that, it was rejected. In addition, those with a breaking elongation of 3% or more were accepted, and those other than that were rejected. The results are shown in Table 3.
〔表面欠陥面積率の測定〕
鋼箔番号１〜８及び１０のＮｉめっき鋼箔の表面欠陥面積率を、前記のフェリシアン化カリウムを用いた試験方法に基づいて測定した。得られた試験片の第１面及び第２面の表面欠陥の写真を撮り、画像解析ソフトＩｍａｇｅＪを用いて二値化処理して、第１面及び第２面の表面欠陥面積率を数値化した。その後、解析機能を用いて青色斑点部の面積率を算出した。結果を表３に示す。
[Measurement of surface defect area ratio]
The surface defect area ratio of the Ni-plated steel foils of steel foil numbers 1 to 8 and 10 was measured based on the above-mentioned test method using potassium ferricyanide. The surface defects on the first and second surfaces of the obtained test piece are photographed and binarized using the image analysis software ImageJ to quantify the surface defect area ratios on the first and second surfaces. bottom. After that, the area ratio of the blue spots was calculated using the analysis function. The results are shown in Table 3.
〔アルカリ中での定電位試験〕
耐金属イオン溶出性を評価するために、鋼箔番号１〜８及び１０の鋼箔及び鋼箔番号９のＮｉ箔に対して、定電位試験を行い、アルカリ中での２４時間後の定電位電流値（μＡ／ｃｍ２）を測定した。
被浸漬サイズ：５０ｍｍ角程度のサンプルの一端に、Ｎｉ線をスポット溶接して、接続部を寺岡製作所製、品番Ｎｏ．６４７、厚み０．０５ｍｍのサーキットテープにて保護した後、６Ｎ（規定）のＫＯＨ試験液を満たした蓋付ポリテトラフルオロエチレン製容器にサンプルを浸漬した。試験温度は６５℃とし、＋０．４Ｖｖｓ．ＳＨＥ、対極：Ｐｔ、参照極：アルカリ用水銀電極（ＢＡＳ製ＲＥ−６１ＡＰ）の条件で電位を印加した。使用装置：北斗電工製ポテンショスタットＨＡ−１５１Ｂを用い、電圧印加２４時間後までの電流変化を測定した。２４時間後の定電位電流値が４μＡ／ｃｍ２以下の場合を合格とし、それ以外を不合格とした。結果を表３に示す。
[Constant potential test in alkali]
In order to evaluate the metal ion elution resistance, a constant potential test was performed on the steel foils of steel foil numbers 1 to 8 and 10 and the Ni foil of steel foil number 9, and the constant potential after 24 hours in alkali was obtained. The current value (μA / cm 2 ) was measured.
Immersion size: Ni wire is spot welded to one end of a sample of about 50 mm square, and the connection part is manufactured by Teraoka Seisakusho Co., Ltd. After protecting with a circuit tape having a thickness of 647 and a thickness of 0.05 mm, the sample was immersed in a container made of polytetrafluoroethylene with a lid filled with a 6N (specified) KOH test solution. The test temperature was 65 ° C. and + 0.4 Vvs. The potential was applied under the conditions of SHE, counter electrode: Pt, and reference electrode: mercury electrode for alkali (RE-61AP manufactured by BAS). Equipment used: A potentiostat HA-151B manufactured by Hokuto Denko was used, and the current change was measured up to 24 hours after the voltage was applied. The case where the constant potential current value after 24 hours was 4 μA / cm 2 or less was regarded as acceptable, and the case where the constant potential current value was 2 or less was regarded as unacceptable. The results are shown in Table 3.
アルカリ中での２４時間後の定電位電流値の評価の基準として、比較例９として純Ｎｉ箔（箔厚み２００μｍ）を用意した。表３に示すように、発明例の鋼箔番号３〜５及び７では、圧延の各パスの単位圧延荷重及び熱処理条件を適正にコントロールすることにより、Ｎｉめっき層の表面欠陥面積率が第１面及び第２面ともに５．００％以下となり、かつ、伸びが３％以上となった。発明例の鋼箔番号４では、アルカリ中での２４時間後の定電位電流値が純Ｎｉ箔（表面欠陥がない場合）と同等のレベルまで改善できた。一方、比較例の鋼箔番号１、２、８では、熱処理の条件が適正範囲を外れているため、Ｎｉめっき層の厚みは本発明の範囲内ではあるものの伸びが低かった。また、比較例の鋼箔番号６では、熱処理温度が高すぎたため、Ｎｉめっき層の表面欠陥面積率が大きくなってしまっており、アルカリ中での２４時間後の定電位電流値が大きく悪化した。比較例の鋼箔番号１０では、圧延加重が高すぎたため、Ｎｉめっき層の表面欠陥面積率が大きくなり、アルカリ中での２４時間後の定電位電流値が大きく悪化した。 As a reference for evaluating the constant potential current value after 24 hours in alkali, a pure Ni foil (foil thickness 200 μm) was prepared as Comparative Example 9. As shown in Table 3, in the steel foil numbers 3 to 5 and 7 of the invention example, the surface defect area ratio of the Ni plating layer is first by appropriately controlling the unit rolling load and the heat treatment conditions of each rolling pass. Both the surface and the second surface were 5.00% or less, and the elongation was 3% or more. In the steel foil No. 4 of the invention example, the constant potential current value after 24 hours in alkali could be improved to the same level as that of the pure Ni foil (when there is no surface defect). On the other hand, in the steel foil numbers 1, 2 and 8 of the comparative example, since the heat treatment conditions were out of the appropriate range, the thickness of the Ni plating layer was within the range of the present invention, but the elongation was low. Further, in the steel foil No. 6 of the comparative example, the heat treatment temperature was too high, so that the surface defect area ratio of the Ni plating layer was large, and the constant potential current value after 24 hours in alkali was greatly deteriorated. .. In the steel foil No. 10 of the comparative example, since the rolling load was too high, the surface defect area ratio of the Ni plating layer became large, and the constant potential current value after 24 hours in alkali was greatly deteriorated.
Claims (5)
Ｃ：０．０００１〜０．０２００％、
Ｓｉ：０．０００１〜０．０２００％、
Ｍｎ：０．００５〜０．３００％、
Ｐ：０．００１〜０．０２０％、
Ｓ：０．０００１〜０．０１００％、
Ａｌ：０．０００５〜０．１０００％、
Ｎ：０．０００１〜０．００４０％、
を含み、
Ｔｉ：０．８００％以下、
Ｎｂ：０．０５０％以下、の１種又は２種を含み、
そして残部がＦｅ及び不純物からなり、Ｎｉめっき層を両面に有するＮｉめっき鋼箔であって、
前記Ｎｉめっき鋼箔の第１面及び第２面のＮｉめっき層の厚みが、それぞれ、０．１５μｍ以上であり、
前記Ｎｉめっき鋼箔の厚みが、５μｍ〜５０μｍであり、
引張強度が４００ＭＰａ超１０００ＭＰａ以下であり、
伸びが３％以上であり、
表面欠陥面積率が前記Ｎｉめっき鋼箔の前記第１面及び前記第２面ともに５．００％以下であることを特徴とするニッケル水素二次電池集電体用Ｎｉめっき鋼箔。 By mass%
C: 0.0001 to 0.0200%,
Si: 0.0001 to 0.0200%,
Mn: 0.005 to 0.300%,
P: 0.001 to 0.020%,
S: 0.0001 to 0.0100%,
Al: 0.0005 to 0.1000%,
N: 0.0001 to 0.0040%,
Including
Ti: 0.800% or less,
Nb: Includes one or two types of 0.050% or less,
The balance is a Ni-plated steel foil composed of Fe and impurities and having a Ni-plated layer on both sides.
The thickness of the Ni-plated layers on the first and second surfaces of the Ni-plated steel foil is 0.15 μm or more, respectively.
The thickness of the Ni-plated steel foil is 5 μm to 50 μm.
The tensile strength is more than 400 MPa and 1000 MPa or less.
Growth is 3% or more,
A Ni-plated steel foil for a nickel-metal hydride secondary battery current collector, wherein the surface defect area ratio is 5.00% or less on both the first surface and the second surface of the Ni-plated steel foil.
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| JP2020065084A JP7475931B2 (en) | 2020-03-31 | 2020-03-31 | Ni-plated steel foil for nickel-hydrogen secondary battery current collector, nickel-hydrogen secondary battery current collector, and nickel-hydrogen secondary battery |
| CN202180026786.2A CN115362580A (en) | 2020-03-31 | 2021-03-24 | Ni-plated steel foil for nickel-metal hydride secondary battery current collector, and nickel-metal hydride secondary battery |
| KR1020227029216A KR20220132580A (en) | 2020-03-31 | 2021-03-24 | Ni-plated steel foil for a nickel hydride secondary battery current collector, a nickel hydride secondary battery current collector, and a nickel hydride secondary battery |
| EP21779519.4A EP4131513A4 (en) | 2020-03-31 | 2021-03-24 | Ni-plated steel foil for nickel hydrogen secondary battery collectors, nickel hydrogen secondary battery collector, and nickel hydrogen secondary battery |
| PCT/JP2021/012383 WO2021200506A1 (en) | 2020-03-31 | 2021-03-24 | Ni-PLATED STEEL FOIL FOR NICKEL HYDROGEN SECONDARY BATTERY COLLECTORS, NICKEL HYDROGEN SECONDARY BATTERY COLLECTOR, AND NICKEL HYDROGEN SECONDARY BATTERY |
| US17/915,435 US20230146305A1 (en) | 2020-03-31 | 2021-03-24 | Ni-plated steel foil for nickel-hydrogen secondary battery current collector, nickel-hydrogen secondary battery current collector, and nickel-hydrogen secondary battery |
| TW110111173A TWI810538B (en) | 2020-03-31 | 2021-03-26 | Ni-plated steel foil for nickel-hydrogen secondary battery current collector, nickel-hydrogen secondary battery current collector, and nickel-hydrogen secondary battery |
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| JP2001085015A (en) | 1999-09-17 | 2001-03-30 | Sumitomo Metal Steel Products Inc | Porous nickel foil for alkaline storage battery negative electrode and manufacture therefor |
| US9997786B2 (en) | 2012-04-19 | 2018-06-12 | Nippon Steel & Sumitomo Metal Corporation | Steel foil and method for manufacturing the same |
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| WO2022231007A1 (en) * | 2021-04-28 | 2022-11-03 | 東洋鋼鈑株式会社 | Surface-treated steel foil |
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