JPH10149824A - Manufacture of hydrogen storage alloy electrode - Google Patents
Manufacture of hydrogen storage alloy electrodeInfo
- Publication number
- JPH10149824A JPH10149824A JP8308938A JP30893896A JPH10149824A JP H10149824 A JPH10149824 A JP H10149824A JP 8308938 A JP8308938 A JP 8308938A JP 30893896 A JP30893896 A JP 30893896A JP H10149824 A JPH10149824 A JP H10149824A
- Authority
- JP
- Japan
- Prior art keywords
- hydrogen storage
- storage alloy
- aqueous solution
- alloy powder
- nickel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000956 alloy Substances 0.000 title claims abstract description 142
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 142
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 116
- 239000001257 hydrogen Substances 0.000 title claims abstract description 116
- 238000003860 storage Methods 0.000 title claims abstract description 114
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 105
- 238000004519 manufacturing process Methods 0.000 title claims description 15
- 239000000843 powder Substances 0.000 claims abstract description 100
- 239000007864 aqueous solution Substances 0.000 claims abstract description 85
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 64
- 230000002378 acidificating effect Effects 0.000 claims abstract description 38
- 229910052751 metal Inorganic materials 0.000 claims abstract description 24
- 239000002184 metal Substances 0.000 claims abstract description 23
- 150000002500 ions Chemical class 0.000 claims abstract description 21
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 16
- 238000000034 method Methods 0.000 claims description 21
- 229910021645 metal ion Inorganic materials 0.000 claims description 3
- 238000011282 treatment Methods 0.000 abstract description 15
- 239000000243 solution Substances 0.000 abstract description 7
- 230000007797 corrosion Effects 0.000 abstract description 5
- 238000005260 corrosion Methods 0.000 abstract description 5
- 239000003792 electrolyte Substances 0.000 abstract description 5
- 239000003929 acidic solution Substances 0.000 abstract description 4
- 229910052782 aluminium Inorganic materials 0.000 abstract description 4
- 238000003411 electrode reaction Methods 0.000 abstract description 4
- 229910052748 manganese Inorganic materials 0.000 abstract description 4
- 150000002739 metals Chemical class 0.000 abstract description 4
- 229920006395 saturated elastomer Polymers 0.000 abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 abstract description 2
- 229910052761 rare earth metal Inorganic materials 0.000 abstract description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 abstract 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 abstract 1
- 239000011572 manganese Substances 0.000 abstract 1
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 23
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 23
- 230000000052 comparative effect Effects 0.000 description 15
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 14
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 11
- 239000002253 acid Substances 0.000 description 9
- 238000010306 acid treatment Methods 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 8
- 150000002431 hydrogen Chemical class 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 229910017604 nitric acid Inorganic materials 0.000 description 6
- 239000000470 constituent Substances 0.000 description 5
- 238000007789 sealing Methods 0.000 description 5
- 238000004381 surface treatment Methods 0.000 description 5
- 150000007513 acids Chemical class 0.000 description 4
- 239000003513 alkali Substances 0.000 description 4
- 238000007654 immersion Methods 0.000 description 4
- XATZQMXOIQGKKV-UHFFFAOYSA-N nickel;hydrochloride Chemical compound Cl.[Ni] XATZQMXOIQGKKV-UHFFFAOYSA-N 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000000977 initiatory effect Effects 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 description 3
- -1 polypropylene Polymers 0.000 description 3
- 229910021503 Cobalt(II) hydroxide Inorganic materials 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 229920001893 acrylonitrile styrene Polymers 0.000 description 2
- 150000001450 anions Chemical class 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- ASKVAEGIVYSGNY-UHFFFAOYSA-L cobalt(ii) hydroxide Chemical compound [OH-].[OH-].[Co+2] ASKVAEGIVYSGNY-UHFFFAOYSA-L 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910052987 metal hydride Inorganic materials 0.000 description 2
- 150000002815 nickel Chemical class 0.000 description 2
- 239000004745 nonwoven fabric Substances 0.000 description 2
- SCUZVMOVTVSBLE-UHFFFAOYSA-N prop-2-enenitrile;styrene Chemical compound C=CC#N.C=CC1=CC=CC=C1 SCUZVMOVTVSBLE-UHFFFAOYSA-N 0.000 description 2
- 238000004080 punching Methods 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- 229910052684 Cerium Inorganic materials 0.000 description 1
- 229910018007 MmNi Inorganic materials 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 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
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- OJIJEKBXJYRIBZ-UHFFFAOYSA-N cadmium nickel Chemical compound [Ni].[Cd] OJIJEKBXJYRIBZ-UHFFFAOYSA-N 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- BFDHFSHZJLFAMC-UHFFFAOYSA-L nickel(ii) hydroxide Chemical compound [OH-].[OH-].[Ni+2] BFDHFSHZJLFAMC-UHFFFAOYSA-L 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
- 229910052726 zirconium Inorganic materials 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
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、水素を可逆的に吸
蔵・放出する水素吸蔵合金を用いた水素吸蔵合金電極の
製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hydrogen storage alloy electrode using a hydrogen storage alloy that reversibly stores and releases hydrogen.
【０００２】[0002]
【従来の技術】近年、可逆的に水素を吸蔵・放出する水
素吸蔵合金粉末を負極に用いたニッケル・水素蓄電池が
エネルギー密度が高く、サイクル寿命も長い二次電池と
して注目されている。近年の二次電池を使用するポータ
ブル機器は、高性能化および多様化が進んでおり、従来
から使用されているニッケル・カドミウム蓄電池などの
二次電池に比べてエネルギー密度やサイクル寿命が優れ
るニッケル・水素蓄電池の生産量はさらに増大すると予
想されている。ニッケル・水素蓄電池の負極には通常、
水素吸蔵合金の粉末を用いて電極を構成したものが使わ
れるので、水素吸蔵合金粉末の特性および電極の構成技
術はニッケル・水素蓄電池の性能に大きな影響を与え
る。2. Description of the Related Art In recent years, a nickel-hydrogen storage battery using a hydrogen storage alloy powder for reversibly storing and releasing hydrogen for a negative electrode has attracted attention as a secondary battery having a high energy density and a long cycle life. In recent years, portable devices using secondary batteries have been improved in performance and diversification, and nickel and cadmium batteries, which have a higher energy density and cycle life than conventional secondary batteries such as nickel-cadmium storage batteries, have been developed. The production of hydrogen storage batteries is expected to increase further. The anode of a nickel-metal hydride battery is usually
Since the electrode composed of the hydrogen storage alloy powder is used, the characteristics of the hydrogen storage alloy powder and the construction technology of the electrode greatly affect the performance of the nickel-metal hydride storage battery.
【０００３】水素吸蔵合金粉末の表面処理方法として、
アルカリ水溶液で合金粉末を洗浄処理することにより、
金属の溶解成分を前もって溶解除去したり、耐食性を向
上させたりする電池の長寿命化技術が使われている（特
公平４−７９４７４号公報、特開昭６１−２３３９６６
号公報）。一方、合金粉末を酸性水溶液に浸漬処理して
水素吸蔵合金粉末表面の酸化層または水酸化物層の量を
調整することにより、長寿命化を図る技術も提案されて
いる（特開平４−１７９０５５号公報）。また、粉砕さ
れた水素吸蔵合金を酸性水溶液で処理した後、アルカリ
水溶液で処理して合金の初期の活性を向上させる方法が
提案されている（特開平３−１５２８６８）。[0003] As a surface treatment method of hydrogen storage alloy powder,
By washing the alloy powder with an alkaline aqueous solution,
A technology for extending the service life of a battery has been used which dissolves and removes dissolved components of metal in advance and improves corrosion resistance (Japanese Patent Publication No. 4-79474, Japanese Patent Application Laid-Open No. 61-233966).
No.). On the other hand, there has been proposed a technique for extending the life of the hydrogen storage alloy powder by adjusting the amount of an oxide layer or a hydroxide layer on the surface of the hydrogen storage alloy powder by immersing the alloy powder in an acidic aqueous solution (Japanese Patent Laid-Open No. 4-179555). No.). Further, a method has been proposed in which a pulverized hydrogen storage alloy is treated with an acidic aqueous solution and then treated with an alkaline aqueous solution to improve the initial activity of the alloy (JP-A-3-152868).
【０００４】上記の技術は、水溶液のｐＨをアルカリ性
または酸性にすることにより、合金の構成金属が溶解し
たり、合金構成金属が水酸化物または酸化物を生成する
性質を利用して合金粉末の表面をエッチング処理するも
のである。合金中の構成金属元素の種類により、酸性ま
たはアルカリ性で溶解しやすい元素と安定な元素があ
る。一般的にＮｉは、電極反応を円滑に進め、電極の高
率放電特性に有効であるため、合金粉末表面に多い方が
好ましい。Ｎｉは、非常にｐＨが高い場合を除いてアル
カリに溶解しにくいが、酸性水溶液中では溶解しやすい
ので、アルカリ処理ではＮｉを表面付近に残すことがで
きるが、酸処理すると溶出してしまう。そのため単に酸
性溶液で処理した合金は、高率放電特性がアルカリ処理
した合金に比べて劣る傾向がある。[0004] In the above-mentioned technique, by making the pH of an aqueous solution alkaline or acidic, the constituent metals of the alloy are dissolved or the constituent metals of the alloy form hydroxides or oxides. The surface is etched. Depending on the type of constituent metal elements in the alloy, there are acidic or alkaline elements that are easily dissolved and stable elements. Generally, Ni is more preferably present on the surface of the alloy powder because Ni promotes the electrode reaction smoothly and is effective for the high-rate discharge characteristics of the electrode. Ni is hardly dissolved in alkali except when the pH is extremely high, but is easily dissolved in an acidic aqueous solution, so that the alkali treatment can leave Ni near the surface, but is eluted by acid treatment. Therefore, alloys simply treated with an acidic solution tend to have inferior high-rate discharge characteristics as compared to alloys treated with alkali.
【０００５】一方、アルカリ中で比較的溶解しにくく、
酸性溶液中でしか溶解しない金属を水素吸蔵合金粉末か
ら溶解させたい場合には、酸処理は有効である。例え
ば、微粉化抑制に効果があるＦｅを含有した水素吸蔵合
金は、電池の長寿命化に有効であるが、Ｆｅは水素吸蔵
合金粉末の表面にあると高温での腐食劣化反応を加速さ
せる。そこで、酸処理を行うと水素吸蔵合金粉末表面の
Ｆｅ濃度を減少させることができ、結果として長寿命の
電極を作製することができる。On the other hand, it is relatively difficult to dissolve in alkali,
The acid treatment is effective when it is desired to dissolve a metal that can be dissolved only in an acidic solution from the hydrogen storage alloy powder. For example, a hydrogen storage alloy containing Fe, which is effective in suppressing pulverization, is effective in prolonging the life of a battery. However, when Fe is present on the surface of the hydrogen storage alloy powder, Fe accelerates a corrosion deterioration reaction at a high temperature. Therefore, when the acid treatment is performed, the Fe concentration on the surface of the hydrogen storage alloy powder can be reduced, and as a result, a long-life electrode can be manufactured.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、従来の
酸処理技術では、上記のような酸処理のメリットを保っ
たまま合金粉末表面にＮｉを残して良好な高率放電特性
を有するなどの、２つ以上の特性を同時に満足させるこ
とが困難であった。本発明は、上記に鑑み、長寿命で高
率放電特性に優れるなどの長所を有するニッケル・水素
蓄電池を与える水素吸蔵合金電極の製造方法、特に水素
吸蔵合金の表面処理方法を提供することを目的とする。However, in the conventional acid treatment technology, Ni has been left on the surface of the alloy powder while maintaining the above-mentioned advantages of the acid treatment, and it has good high-rate discharge characteristics. It has been difficult to satisfy one or more properties simultaneously. In view of the above, an object of the present invention is to provide a method for manufacturing a hydrogen storage alloy electrode that provides a nickel-hydrogen storage battery having advantages such as long life and excellent high-rate discharge characteristics, and in particular, to provide a surface treatment method for a hydrogen storage alloy. And
【０００７】[0007]
【課題を解決するための手段】この課題を解決するた
め、本発明の水素吸蔵合金電極の製造方法は、水素吸蔵
合金の粉末を、その水素吸蔵合金を構成する少なくとも
１種の金属のイオンを含有している酸性水溶液中に浸漬
処理する工程、および前記処理を経た水素吸蔵合金粉末
を用いて電極を作成する工程を有する。ここにおいて、
前記金属イオンは、Ｎｉ2+イオンであることが好まし
い。また、本発明は、ニッケルを１成分とする水素吸蔵
合金の粉末からなる電極を、Ｎｉ2+イオンを含有してい
る酸性水溶液中に浸漬処理する工程を有する水素吸蔵合
金電極の製造方法を提供する。In order to solve this problem, a method of manufacturing a hydrogen storage alloy electrode according to the present invention comprises the steps of: preparing a powder of a hydrogen storage alloy by converting ions of at least one metal constituting the hydrogen storage alloy; The method includes a step of immersion treatment in the contained acidic aqueous solution, and a step of forming an electrode using the hydrogen storage alloy powder that has been subjected to the treatment. put it here,
The metal ions are preferably Ni 2+ ions. Further, the present invention provides a method for producing a hydrogen storage alloy electrode, which comprises a step of immersing an electrode made of a powder of a hydrogen storage alloy containing nickel as one component in an acidic aqueous solution containing Ni 2+ ions. I do.
【０００８】[0008]
【発明の実施の形態】水素吸蔵合金粉末を酸処理する
と、ほとんどの構成金属は溶解するので、合金粉末表面
はエッチングされる。表面が酸化している水素吸蔵合金
粉末でも、酸処理することにより表面の酸化膜がとれる
ので合金の新生面が現れ、電極反応が活性になると考え
られる。しかしながら、単に酸性水溶液で処理した合金
は、電池を構成した後アルカリ電解液に接触すると、す
ぐにその表面が腐食し、Ａｌ、Ｍｎ等は溶解し、希土類
等の合金構成元素の酸化物や水酸化物で覆われてしま
う。本発明の酸処理では、例えばＮｉ2+イオンがあらか
じめ酸性水溶液中に飽和濃度で溶解している酸性水溶液
を用いると、Ｎｉがそれ以上溶解しにくくなるので水素
吸蔵合金粉末の表面でＮｉ金属リッチな層を表面に残し
た状態でエッチングをすることができる。DESCRIPTION OF THE PREFERRED EMBODIMENTS When a hydrogen storage alloy powder is subjected to an acid treatment, most of the constituent metals are dissolved, so that the surface of the alloy powder is etched. It is considered that even with a hydrogen storage alloy powder whose surface is oxidized, an oxide film on the surface can be removed by the acid treatment, so that a new surface of the alloy appears and the electrode reaction becomes active. However, when an alloy simply treated with an acidic aqueous solution is brought into contact with an alkaline electrolyte after forming a battery, its surface is immediately corroded, Al, Mn, etc. are dissolved, and oxides and water of alloy constituent elements such as rare earth elements are dissolved. It will be covered with oxide. In the acid treatment of the present invention, for example, when an acidic aqueous solution in which Ni 2+ ions are previously dissolved at a saturated concentration in an acidic aqueous solution is used, Ni is less likely to be further dissolved, so that Ni metal rich on the surface of the hydrogen storage alloy powder. Etching can be performed with the proper layer left on the surface.
【０００９】本発明の方法により製造した水素吸蔵合金
電極を用いて電池を構成した場合、Ｎｉはアルカリ電解
液中でも比較的安定であるので、Ｎｉリッチな層に水素
吸蔵合金が守られて、腐食しにくくなって電池サイクル
寿命が改善される。さらに、導電性の高いＮｉが表面に
存在することから、電極反応が円滑に進み、良好な充放
電特性を得ることができる。ここではＮｉの場合につい
て説明したが、本発明の製造方法によれば、Ｎｉ以外の
金属リッチな表面を有する水素吸蔵合金粉末とすること
が可能であり、その金属の種類により、耐食性の向上
や、初期活性の向上などのメリットを持ったニッケル・
水素蓄電池を提供することができる。When a battery is formed using the hydrogen storage alloy electrode manufactured by the method of the present invention, Ni is relatively stable even in an alkaline electrolyte. And the battery cycle life is improved. Further, since the highly conductive Ni is present on the surface, the electrode reaction proceeds smoothly, and good charge / discharge characteristics can be obtained. Although the case of Ni has been described here, according to the manufacturing method of the present invention, it is possible to use a hydrogen storage alloy powder having a metal-rich surface other than Ni. Nickel with advantages such as improved initial activity
A hydrogen storage battery can be provided.
【００１０】本発明において、電極を構成するための水
素吸蔵合金粉末または電極を構成している水素吸蔵合金
を処理する酸性水溶液として、Ｎｉ2+を含む水溶液を用
いる場合、Ｎｉ2+イオン濃度は飽和濃度の２０％以上の
濃度であることが好ましい。Ｎｉ2+を含む水溶液は、硫
酸ニッケル、硝酸ニッケル、塩酸ニッケルのいずれかの
水溶液から調製するのがよい。また、上記の酸性水溶液
は、そのｐＨが４以下であることが好ましい。この酸性
水溶液は、２種類以上の酸からなる水溶液であることが
好ましい。酸性水溶液中で処理した水素吸蔵合金粉末ま
たは電極は、必要に応じて水洗する。本発明により水素
吸蔵合金粉末を用いて電極を製造する方法は、既知の非
燒結式電極の製造方法を適用することができる。すなわ
ち、水素吸蔵合金粉末をペースト状にして発泡メタルや
金属繊維の不織布などの三次元多孔体に充填する方法、
あるいは結着剤とともに湿式あるいは乾式でパンチング
メタルや金属シートに塗着する方法などである。In the present invention, when an aqueous solution containing Ni 2+ is used as the acidic aqueous solution for treating the hydrogen storage alloy powder for forming the electrode or the hydrogen storage alloy forming the electrode, the Ni 2+ ion concentration is The concentration is preferably 20% or more of the saturation concentration. The aqueous solution containing Ni 2+ is preferably prepared from an aqueous solution of any of nickel sulfate, nickel nitrate and nickel hydrochloride. The pH of the acidic aqueous solution is preferably 4 or less. This acidic aqueous solution is preferably an aqueous solution composed of two or more acids. The hydrogen storage alloy powder or the electrode treated in the acidic aqueous solution is washed with water as necessary. As a method of manufacturing an electrode using the hydrogen storage alloy powder according to the present invention, a known method of manufacturing a non-sintered electrode can be applied. That is, a method of filling a three-dimensional porous body such as a foamed metal or a non-woven fabric of a metal fiber into a paste-like hydrogen storage alloy powder,
Alternatively, there is a method in which a wet or dry method is applied to a punching metal or metal sheet together with a binder.
【００１１】[0011]
【実施例】以下に、実施例により本発明の水素吸蔵合金
電極の製造方法について詳しく説明する。 《実施例１》 （１）水素吸蔵合金粉末の表面処理 次のようにして作製した水素吸蔵合金粉末に表面処理を
行った。すなわち、Ｍｍ（Ｌａ、Ｃｅ、Ｎｄ、Ｐｒから
なる合金）、Ｎｉ、Ｍｎ、Ａｌ、およびＦｅの各成分元
素を所定の割合で混合し、高周波溶解炉で組成ＭｍＮｉ
3.9Ｍｎ0.4Ａｌ0.4Ｆｅ0.3の水素吸蔵合金のインゴット
を作製した。この合金インゴットをＡｒ雰囲気下、１０
００℃で１０時間熱処理した後、このインゴットを粉砕
して平均粒径３０μｍの水素吸蔵合金粉末を作製した。
１.５ｍｏｌ／ｌの硫酸ニッケル水溶液を調製し、この
硫酸ニッケル水溶液５００ｍｌ中に上記の水素吸蔵合金
粉末３００ｇを浸漬し、室温において撹拌機で約１時間
撹拌した。このとき調製された硫酸ニッケル水溶液のｐ
Ｈは３程度であった。浸漬処理後の水素吸蔵合金は十分
に水洗した後、乾燥して負極作製用の水素吸蔵合金粉末
とした。EXAMPLES The method for producing the hydrogen storage alloy electrode of the present invention will be described in detail below with reference to examples. << Example 1 >> (1) Surface treatment of hydrogen storage alloy powder The hydrogen storage alloy powder produced as described below was subjected to surface treatment. That is, Mm (an alloy composed of La, Ce, Nd, and Pr), Ni, Mn, Al, and Fe are mixed at a predetermined ratio, and the composition MmNi is mixed in a high-frequency melting furnace.
An ingot of a hydrogen storage alloy of 3.9 Mn 0.4 Al 0.4 Fe 0.3 was produced. This alloy ingot was placed in an Ar atmosphere at 10
After heat treatment at 00 ° C. for 10 hours, the ingot was pulverized to produce a hydrogen storage alloy powder having an average particle diameter of 30 μm.
A 1.5 mol / l nickel sulfate aqueous solution was prepared, and 300 g of the above-mentioned hydrogen storage alloy powder was immersed in 500 ml of the nickel sulfate aqueous solution, followed by stirring at room temperature with a stirrer for about 1 hour. P of the aqueous nickel sulfate solution prepared at this time
H was about 3. The hydrogen storage alloy after the immersion treatment was sufficiently washed with water and then dried to obtain a hydrogen storage alloy powder for producing a negative electrode.
【００１２】（２）評価用電池の作製 次に、上記により作製された水素吸蔵合金粉末を用い
て、正極により容量が規制された、液スターブ密閉式の
ニッケル・水素蓄電池を作製した。水酸化ニッケルと金
属コバルトと水酸化コバルトと酸化亜鉛を重量比で１０
０：７：５：２．５の割合に秤量した粉末を良く混合し
た後、この混合粉末２０ｇに水を添加しペースト状にし
た。縦８１ｍｍ、横６０ｍｍ、重量３．１ｇの発泡ニッ
ケル中に、このペーストを充填し乾燥後、厚み１．７４
ｍｍに圧縮し正極板とした。正極板の角にリードとして
のニッケル板をスポット溶接した。金属コバルトは放電
リザーブの確保に寄与し、水酸化コバルトは充電効率の
改良に寄与する。この正極板１枚の理論容量は５．０５
Ａｈである。試験用電池にはこの正極板を５枚用いた。
負極には前記のように作製した水素吸蔵合金粉末を用い
た。この水素吸蔵合金粉末１９．４ｇにカルボキシメチ
ルセルロースとスチレンブタジエン共重合体と水を１０
０：０.５：１：２０の重量比になるように加えて練合
しペーストとした。縦８１ｍｍ、横６０ｍｍ、重量２．
１ｇのパンチングメタルに、このペーストを塗着し乾燥
後、厚み１．２０ｍｍまでロールプレスして負極板とし
た。負極板の角にリードとしてのニッケル板をスポット
溶接した。この負極板１枚の理論容量は５．６３Ａｈで
ある。試験用電池にはこの負極板を６枚用いた。(2) Production of Battery for Evaluation Next, using the hydrogen storage alloy powder produced as described above, a nickel-hydrogen storage battery of a sealed liquid starve type whose capacity was regulated by the positive electrode was produced. Nickel hydroxide, metallic cobalt, cobalt hydroxide and zinc oxide in a weight ratio of 10
After powders weighed in a ratio of 0: 7: 5: 2.5 were mixed well, water was added to 20 g of the mixed powder to form a paste. This paste is filled in a foamed nickel foam having a length of 81 mm, a width of 60 mm and a weight of 3.1 g, and after drying, has a thickness of 1.74.
mm to obtain a positive electrode plate. A nickel plate as a lead was spot-welded to a corner of the positive electrode plate. Metallic cobalt contributes to securing a discharge reserve, and cobalt hydroxide contributes to improvement of charging efficiency. The theoretical capacity of one positive electrode plate is 5.05.
Ah. Five positive electrodes were used for a test battery.
The hydrogen storage alloy powder produced as described above was used for the negative electrode. To 19.4 g of the hydrogen storage alloy powder, 10 parts of carboxymethyl cellulose, styrene butadiene copolymer and water were added.
The mixture was kneaded with a mixture in a weight ratio of 0: 0.5: 1: 20 to obtain a paste. 81 mm long, 60 mm wide, weight 2.
This paste was applied to 1 g of punching metal, dried, and then roll-pressed to a thickness of 1.20 mm to obtain a negative electrode plate. A nickel plate as a lead was spot-welded to a corner of the negative electrode plate. The theoretical capacity of one negative electrode plate is 5.63 Ah. Six negative electrodes were used for a test battery.
【００１３】図１のように、スルホン化処理をしたポリ
プロピレン不織布からなるセパレータ１を介して、負極
２と正極３を交互に積層し、外側に負極がくるように配
置した。負極のリードをニッケル製負極端子４に、正極
のリードをニッケル製正極端子（図示しない）にそれぞ
れスポット溶接した。これらの極板群を厚み５ｍｍのア
クリロニトリルースチレン樹脂からなる縦１０８ｍｍ、
横６９ｍｍ、幅１８ｍｍのケース５に収納した。水酸化
カリウムを主体とした比重１．３のアルカリ水溶液から
なる電解液を５４ｃｃ注入した後、ケース５の開口部に
アクリロニトリルースチレン樹脂からなる封口板７をエ
ポキシ樹脂で接着して封口した。封口板７には、３気圧
で作動する安全弁６が取り付けてある。また、負極端子
４は、ナット９で締め付けることによりＯリング８を介
して封口板７に圧接固定してある。正極端子も同様にし
て封口板に気密かつ液密に取り付けられている。こうし
て密閉電池を作製した。As shown in FIG. 1, negative electrodes 2 and positive electrodes 3 were alternately laminated via a separator 1 made of a sulfonated polypropylene nonwoven fabric, and the negative electrodes 2 and 3 were arranged so that the negative electrodes were on the outside. The negative electrode lead was spot-welded to the nickel negative electrode terminal 4, and the positive electrode lead was spot-welded to the nickel positive electrode terminal (not shown). These electrode plates were made of acrylonitrile styrene resin having a thickness of 5 mm, length 108 mm,
It was stored in a case 5 having a width of 69 mm and a width of 18 mm. After injecting 54 cc of an electrolytic solution composed of an alkaline aqueous solution mainly composed of potassium hydroxide and having a specific gravity of 1.3, a sealing plate 7 made of acrylonitrile styrene resin was adhered to the opening of the case 5 with an epoxy resin and sealed. A safety valve 6 operating at 3 atm is attached to the sealing plate 7. Further, the negative electrode terminal 4 is fixed to the sealing plate 7 by O-ring 8 by pressing with a nut 9. The positive electrode terminal is similarly air-tightly and liquid-tightly attached to the sealing plate. Thus, a sealed battery was produced.
【００１４】（３）電池の評価 試験用電池について、充放電試験をしてサイクル寿命を
調べた。充放電試験は、３時間率（８.４３Ａ）で１時
間充電し、同じく３時間率で端子電圧が１Ｖになるまで
放電する充放電を繰り返した。そして、５０サイクル毎
に、放電容量を測定し、放電容量が初期容量（５サイク
ル目）の９０％に劣化するまでのサイクル数をもって寿
命とした。なお、放電容量は、室温において、１０時間
率（２.５３Ａ）で１２時間充電した後、５時間率（５.
０６Ａ）で端子間電圧が１Ｖになるまでの放電時間から
求めた。また、高率放電特性として、０．５時間率で放
電して求めた放電容量の前記１０時間率放電容量に対す
る百分率で表した。これらの試験結果を表１に示す。(3) Evaluation of Battery The battery for test was subjected to a charge / discharge test to examine the cycle life. In the charge / discharge test, charge / discharge in which the battery was charged at a 3-hour rate (8.43 A) for 1 hour and then discharged until the terminal voltage became 1 V at a 3-hour rate was repeated. The discharge capacity was measured every 50 cycles, and the number of cycles until the discharge capacity was reduced to 90% of the initial capacity (fifth cycle) was defined as the life. The discharge capacity was determined at room temperature by charging for 12 hours at a rate of 10 hours (2.53 A) and then at a rate of 5 hours (5.5.
06A) from the discharge time until the inter-terminal voltage becomes 1 V. Further, as the high rate discharge characteristics, the discharge capacity obtained by discharging at a 0.5 hour rate was expressed as a percentage with respect to the 10 hour rate discharge capacity. Table 1 shows the test results.
【００１５】《実施例２》１．５ｍｏｌ／ｌの硝酸ニッ
ケル水溶液を調製し、この硝酸ニッケル水溶液５００ｍ
ｌ中に、実施例１と同様の水素吸蔵合金粉末を３００ｇ
浸漬し、室温で約１時間撹拌し、負極用の水素吸蔵合金
粉末を作製した。この水素吸蔵合金粉末を用いて実施例
１と同様にして電池を作製した。Example 2 A 1.5 mol / l nickel nitrate aqueous solution was prepared, and the nickel nitrate aqueous solution 500 m
1 g of the same hydrogen storage alloy powder as in Example 1
It was immersed and stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode. A battery was produced in the same manner as in Example 1 using this hydrogen storage alloy powder.
【００１６】《実施例３》１．５ｍｏｌ／ｌの塩化ニッ
ケル水溶液５００ｍｌ中に実施例１と同じ水素吸蔵合金
粉末を３００ｇ浸漬し、室温で約１時間撹拌することに
より負極用の水素吸蔵合金粉末を作製し、電池を作製し
た。Example 3 300 g of the same hydrogen storage alloy powder as in Example 1 was immersed in 500 ml of a 1.5 mol / l nickel chloride aqueous solution, and stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode. Was produced, and a battery was produced.
【００１７】《実施例４》１．５ｍｏｌ／ｌの硫酸ニッ
ケル水溶液と１．５ｍｏｌ／ｌの硝酸ニッケル水溶液を
調製し、この２種類の水溶液を２５０ｍｌずつ計りとり
混合した。この硫酸ニッケルと硝酸ニッケルの混合水溶
液５００ｍｌ中に実施例１と同じ水素吸蔵合金粉末を３
００ｇ浸漬し、室温で約１時間撹拌して負極用の水素吸
蔵合金粉末を作製した。この水素吸蔵合金粉末を用いて
実施例１と同様にして電池を作製した。Example 4 A 1.5 mol / l aqueous solution of nickel sulfate and a 1.5 mol / l aqueous solution of nickel nitrate were prepared, and the two aqueous solutions were weighed and mixed in 250 ml each. The same hydrogen storage alloy powder as in Example 1 was placed in 500 ml of the mixed aqueous solution of nickel sulfate and nickel nitrate.
Then, the resultant was immersed in 00 g and stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode. A battery was produced in the same manner as in Example 1 using this hydrogen storage alloy powder.
【００１８】《実施例５》１．５ｍｏｌ／ｌの硫酸ニッ
ケル水溶液と１．５ｍｏｌ／ｌの塩酸ニッケル水溶液を
調製し、この２種類の水溶液を２５０ｍｌずつ計りとり
混合した。この硫酸ニッケルと塩酸ニッケルの混合水溶
液５００ｍｌ中に実施例１と同じ水素吸蔵合金粉末を３
００ｇ浸漬し、室温で約１時間撹拌して負極用の水素吸
蔵合金粉末を作製した。この水素吸蔵合金粉末を用いて
実施例１と同様にして電池を作製した。Example 5 A 1.5 mol / l aqueous solution of nickel sulfate and a 1.5 mol / l aqueous solution of nickel hydrochloride were prepared, and the two aqueous solutions were weighed and mixed in 250 ml portions. The same hydrogen storage alloy powder as in Example 1 was placed in 500 ml of the mixed aqueous solution of nickel sulfate and nickel chloride.
Then, the resultant was immersed in 00 g and stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode. A battery was produced in the same manner as in Example 1 using this hydrogen storage alloy powder.
【００１９】《実施例６》１．５ｍｏｌ／ｌの硝酸ニッ
ケル水溶液と１．５ｍｏｌ／ｌの塩酸ニッケル水溶液を
調製し、この２種類の水溶液を２５０ｍｌずつ計りとり
混合した。この硝酸ニッケルと塩酸ニッケルの混合水溶
液５００ｍｌ中に実施例１と同じ水素吸蔵合金粉末を３
００ｇ浸漬し、室温で約１時間撹拌して負極用の水素吸
蔵合金粉末を作製した。この水素吸蔵合金粉末を用いて
実施例１と同様にして電池を作製した。Example 6 A 1.5 mol / l aqueous solution of nickel nitrate and a 1.5 mol / l aqueous solution of nickel hydrochloride were prepared, and the two types of aqueous solutions were weighed and mixed in 250 ml each. The same hydrogen storage alloy powder as in Example 1 was placed in 500 ml of this mixed aqueous solution of nickel nitrate and nickel hydrochloride.
Then, the resultant was immersed in 00 g and stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode. A battery was produced in the same manner as in Example 1 using this hydrogen storage alloy powder.
【００２０】《実施例７》１．５ｍｏｌ／ｌの硫酸ニッ
ケル水溶液を調製し、この硫酸ニッケル水溶液に金属Ｎ
ｉの微粉末を過剰に浸漬し１週間放置した。その後、Ｎ
ｉ微粉末をろ過して取り除き、このろ液５００ｍｌ中に
実施例１と同じ水素吸蔵合金粉末を３００ｇ浸漬し、室
温で約１時間撹拌して負極用の水素吸蔵合金粉末を作製
した。この水素吸蔵合金粉末を用いて実施例１と同様に
して電池を作製した。Example 7 A 1.5 mol / l aqueous solution of nickel sulfate was prepared, and the aqueous solution of nickel sulfate was added to the aqueous solution of nickel sulfate.
The fine powder of i was immersed in excess and left for one week. Then N
The fine powder was removed by filtration, and 300 g of the same hydrogen storage alloy powder as in Example 1 was immersed in 500 ml of the filtrate and stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode. A battery was produced in the same manner as in Example 1 using this hydrogen storage alloy powder.
【００２１】《比較例１》実施例１と同様の方法で水素
吸蔵合金を作製し、粉砕後の水素吸蔵合金粉末には全く
表面処理を施さずに実施例１と同様の方法で電池を作製
した。<< Comparative Example 1 >> A hydrogen storage alloy was produced in the same manner as in Example 1, and a battery was produced in the same manner as in Example 1 without performing any surface treatment on the pulverized hydrogen storage alloy powder. did.
【００２２】《比較例２》１．５ｍｏｌ／ｌの硫酸水溶
液を調製し、この硫酸水溶液５００ｍｌ中に実施例１と
同じ水素吸蔵合金粉末を３００ｇ浸漬し、撹拌機で室温
で約１時間撹拌し、負極用の水素吸蔵合金粉末を作製し
た。この水素吸蔵合金粉末を用いて実施例１と同様にし
て電池を作製した。Comparative Example 2 A 1.5 mol / l sulfuric acid aqueous solution was prepared, and 300 g of the same hydrogen storage alloy powder as in Example 1 was immersed in 500 ml of the sulfuric acid aqueous solution, followed by stirring for about 1 hour at room temperature with a stirrer. Then, a hydrogen storage alloy powder for a negative electrode was produced. A battery was produced in the same manner as in Example 1 using this hydrogen storage alloy powder.
【００２３】《比較例３》１．５ｍｏｌ／ｌの硝酸水溶
液５００ｍｌ中に実施例１と同じ水素吸蔵合金粉末を３
００ｇ浸漬し、室温で約１時間撹拌することにより負極
用の水素吸蔵合金粉末を作製し、電池を作製した。Comparative Example 3 The same hydrogen storage alloy powder as in Example 1 was added to 500 ml of a 1.5 mol / l nitric acid aqueous solution.
By immersing in 00 g and stirring at room temperature for about 1 hour, a hydrogen storage alloy powder for a negative electrode was produced, and a battery was produced.
【００２４】《比較例４》１．５ｍｏｌ／ｌの塩酸水溶
液５００ｍｌ中に実施例１と同じ水素吸蔵合金粉末を３
００ｇ浸漬し、室温で約１時間撹拌することにより負極
用の水素吸蔵合金粉末を作製し、電池を作製した。Comparative Example 4 The same hydrogen storage alloy powder as in Example 1 was placed in 500 ml of a 1.5 mol / l hydrochloric acid aqueous solution.
By immersing in 00 g and stirring at room temperature for about 1 hour, a hydrogen storage alloy powder for a negative electrode was produced, and a battery was produced.
【００２５】《比較例５》実施例１の硫酸ニッケル水溶
液と同じｐＨ（すなわちｐＨ３）の硫酸水溶液を調製
し、この硫酸水溶液５００ｍｌ中に実施例１と同じ水素
吸蔵合金粉末を３００ｇ浸漬し、室温で約１時間撹拌し
て負極用の水素吸蔵合金粉末を作製した。この水素吸蔵
合金粉末を用いて実施例１と同様にして電池を作製し
た。Comparative Example 5 A sulfuric acid aqueous solution having the same pH (ie, pH 3) as the nickel sulfate aqueous solution of Example 1 was prepared, and 300 g of the same hydrogen storage alloy powder as in Example 1 was immersed in 500 ml of this sulfuric acid aqueous solution. For about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode. A battery was produced in the same manner as in Example 1 using this hydrogen storage alloy powder.
【００２６】《比較例６》実施例２の硝酸ニッケル水溶
液と同じｐＨの硝酸水溶液を調製し、この水溶液５００
ｍｌ中に実施例１と同じ水素吸蔵合金粉末を３００ｇ浸
漬し、室温で約１時間撹拌して負極用の水素吸蔵合金粉
末を作製し、電池を作製した。Comparative Example 6 An aqueous solution of nitric acid having the same pH as the aqueous solution of nickel nitrate of Example 2 was prepared.
300 g of the same hydrogen storage alloy powder as in Example 1 was immersed in the resulting mixture, and the mixture was stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode to prepare a battery.
【００２７】《比較例７》実施例３の塩酸ニッケル水溶
液と同じｐＨの塩酸水溶液を調製し、この水溶液５００
ｍｌ中に実施例１と同じ水素吸蔵合金粉末を３００ｇ浸
漬し、室温で約１時間撹拌して負極用の水素吸蔵合金粉
末を作製し、電池を作製した。Comparative Example 7 An aqueous hydrochloric acid solution having the same pH as the aqueous nickel chloride solution of Example 3 was prepared.
300 g of the same hydrogen storage alloy powder as in Example 1 was immersed in the resulting mixture, and the mixture was stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode to prepare a battery.
【００２８】以上の実施例および比較例の電池のサイク
ル寿命および高率放電特性を表１に示す。Table 1 shows the cycle life and high-rate discharge characteristics of the batteries of the above Examples and Comparative Examples.
【００２９】[0029]
【表１】 [Table 1]
【００３０】まず、実施例１〜３と比較例１を比べる
と、本発明の水素吸蔵合金粉末の処理方法によって、未
処理の水素吸蔵合金粉末を使用した電池に比べて電池寿
命が大幅に長くなり、高率放電特性も向上することがわ
かる。次に、実施例１〜３を比較例２〜４と比べると、
単に水素吸蔵合金粉末を酸性水溶液に浸漬した処理に比
べて、本発明の処理方法を適用した水素吸蔵合金粉末を
用いた電池は、寿命と高率放電特性に優れており、本発
明の方法で処理された水素吸蔵合金粉末が耐食性に優れ
電気化学的に活性な粉末であることがわかる。比較例２
〜４の硫酸イオン、硝酸イオン、塩酸イオンは実施例１
〜３の水溶液とほぼ等モル存在するが、比較例２〜４の
方がｐＨが小さく酸性が強い。そこで、実施例１〜３と
ｐＨを同じにした酸性水溶液で水素吸蔵合金粉末を処理
した比較例５〜７を、実施例１〜３と比較すると、やは
り本発明の処理方法を適用した合金粉末を用いた電池の
方が寿命、高率放電特性ともに優秀であり、特に寿命特
性の優位性が大きい。なお、ここでは硫酸、硝酸、塩酸
の酸性水溶液について説明したが、他の強酸および酢酸
やほう酸等の弱酸をベースにしたニッケル塩溶液を使用
した場合でも同様の傾向が観察され、本発明の方法によ
り寿命や放電率特性を向上させることができる。First, comparing Examples 1 to 3 with Comparative Example 1, the method of treating the hydrogen-absorbing alloy powder of the present invention greatly increases the battery life as compared with a battery using untreated hydrogen-absorbing alloy powder. It can be seen that the high rate discharge characteristics are also improved. Next, when Examples 1-3 are compared with Comparative Examples 2-4,
Compared to a process in which the hydrogen storage alloy powder is simply immersed in an acidic aqueous solution, a battery using the hydrogen storage alloy powder to which the treatment method of the present invention is applied has excellent life and high-rate discharge characteristics. It is understood that the treated hydrogen storage alloy powder has excellent corrosion resistance and is an electrochemically active powder. Comparative Example 2
The sulfate, nitrate, and hydrochloric acid ions of Examples 1 to 4
Although they are almost equimolar to the aqueous solutions of Comparative Examples 2 to 3, Comparative Examples 2 to 4 have lower pH and higher acidity. Therefore, when comparing Comparative Examples 5 to 7 in which the hydrogen storage alloy powder was treated with an acidic aqueous solution having the same pH as those in Examples 1 to 3, to Examples 1 to 3, the alloy powder to which the treatment method of the present invention was applied was also used. Batteries using are superior in both life and high-rate discharge characteristics, and particularly superior in life characteristics. Here, sulfuric acid, nitric acid, an acidic aqueous solution of hydrochloric acid has been described, but the same tendency is observed when a nickel salt solution based on another strong acid and a weak acid such as acetic acid or boric acid is used, and the method of the present invention is used. As a result, the life and discharge rate characteristics can be improved.
【００３１】次に、酸性水溶液を構成する陰イオンが２
種類以上である場合について説明する。実施例４〜６を
実施例１〜３および比較例と比べると、酸性水溶液を構
成する陰イオンが２種類以上であってもサイクル寿命や
高率放電特性は優秀であり、２種類以上の酸の混合水溶
液の方が１種類の酸性水溶液より良好な特性を得ること
ができる。なお、ここでは２種類の酸性水溶液を混合し
た例を用いて説明したが、３種類以上の酸性水溶液を混
合しても非常に良好な電池特性が得られる。また、酸の
種類は硫酸、硝酸、塩酸以外でもよい。なお、実施例４
〜６では２種類の酸のニッケル塩の水溶液を等量ずつ混
合しているが、混合割合が変わっても同様の効果が得ら
れる。Next, the anion constituting the acidic aqueous solution is 2
The case where the number is more than the types will be described. When Examples 4 to 6 are compared with Examples 1 to 3 and Comparative Example, the cycle life and high-rate discharge characteristics are excellent even when the acidic aqueous solution contains two or more types of anions, and two or more types of acids are used. The mixed aqueous solution can obtain better characteristics than one kind of acidic aqueous solution. Although an example in which two kinds of acidic aqueous solutions are mixed has been described here, even if three or more kinds of acidic aqueous solutions are mixed, very good battery characteristics can be obtained. The type of acid may be other than sulfuric acid, nitric acid and hydrochloric acid. Example 4
In Nos. 6 to 6, the aqueous solutions of two types of nickel salts of acids are mixed in equal amounts, but the same effect can be obtained even if the mixing ratio is changed.
【００３２】次に、Ｎｉ2+イオン濃度と本発明の効果の
関係について説明する。実施例７と実施例１を比較する
と、実施例７の方が寿命特性に優れていることがわか
る。実施例７は、Ｎｉ金属をあらかじめ溶解させている
ので、実施例１に比べてＮｉ
2+イオン濃度が高い。Ｎｉ微粉末の浸漬時間を変えてい
ろいろなＮｉ 2+イオンの濃度を試したところ、Ｎｉ2+イ
オン濃度が高く、飽和濃度に近いほど寿命特性と高率放
電特性の良好な電池が得られたことから、水素吸蔵合金
粉末の表面がよりＮｉリッチなものが作製できたと推察
される。なお、ここでは硫酸ニッケル水溶液の実施例を
示したが、硝酸、塩酸、その他の酸でもＮｉ2+イオン濃
度が高い方がよい。Next, the relationship between the Ni 2+ ion concentration and the effect of the present invention will be described. Comparing Example 7 with Example 1, it can be seen that Example 7 has better life characteristics. In the seventh embodiment, Ni metal is dissolved in advance, so that Ni metal is compared with the first embodiment.
High 2+ ion concentration. Changing the immersion time of the Ni fine powder
When the concentration of various Ni 2+ ions was tested, the higher the Ni 2+ ion concentration and the closer to the saturation concentration, the better the battery life and high-rate discharge characteristics were obtained. It is presumed that a Ni-rich surface could be produced. Although the example of the nickel sulfate aqueous solution is shown here, it is preferable that nitric acid, hydrochloric acid and other acids have a high Ni 2+ ion concentration.
【００３３】《実施例８》０．５〜２．０ｍｏｌ／ｌの
濃度の異なる硫酸ニッケル水溶液と、硫酸ニッケルの飽
和水溶液を調製し、これらの硫酸ニッケル水溶液それぞ
れ５００ｍｌ中に実施例１と同じ水素吸蔵合金粉末を３
００ｇ浸漬し、室温で約１時間撹拌して負極用の水素吸
蔵合金粉末を作製した。これらの水素吸蔵合金粉末を用
いて実施例１と同様にして電池を作製した。これらの電
池を前記と同様の条件で評価した結果を表２に示す。処
理に用いる硫酸ニッケル水溶液の濃度が高い方がサイク
ル寿命と高率放電特性が向上する。実施例７および実施
例８から判断すると、Ｎｉ2+イオンの濃度が薄すぎては
効果が小さいので、酸性水溶液中のＮｉ2+イオンの濃度
はおおよそ飽和濃度の２０％以上であることが望まし
い。Example 8 An aqueous solution of nickel sulfate having a different concentration of 0.5 to 2.0 mol / l and a saturated aqueous solution of nickel sulfate were prepared, and the same hydrogen solution as in Example 1 was added to each 500 ml of the aqueous solution of nickel sulfate. 3 occlusion alloy powders
Then, the resultant was immersed in 00 g and stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode. A battery was produced in the same manner as in Example 1 using these hydrogen storage alloy powders. Table 2 shows the results of evaluating these batteries under the same conditions as described above. The higher the concentration of the aqueous nickel sulfate solution used for the treatment, the better the cycle life and the high rate discharge characteristics. Judging from Examples 7 and 8, since the effect is small if the concentration of Ni 2+ ions is too low, the concentration of Ni 2+ ions in the acidic aqueous solution is preferably about 20% or more of the saturated concentration. .
【００３４】[0034]
【表２】 [Table 2]
【００３５】《実施例９》１．５ｍｏｌ／ｌの硫酸ニッ
ケル水溶液を調製し、この硫酸ニッケル水溶液にイオン
交換水または硫酸を添加することによりｐＨ０．５〜ｐ
Ｈ６までの硫酸ニッケル水溶液を作製した。これらの硫
酸ニッケル水溶液それぞれ５００ｍｌ中に実施例１と同
じ水素吸蔵合金粉末を３００ｇ浸漬し、室温で約１時間
撹拌し、負極用の水素吸蔵合金粉末を作製した。これら
の水素吸蔵合金粉末を用いて実施例１と同様にして電池
を作製した。これらの電池を前記と同様の条件で評価し
た結果を表３に示す。ｐＨが大きすぎると表面から溶解
させたい金属のエッチング効果が小さくなるので、処理
に用いる酸性水溶液のｐＨは４以下であることが望まし
い。なお、ここでは酸性水溶液のｐＨを変えるために同
一種の酸を加えたが、硝酸等の別の酸を加えてもよい。Example 9 A 1.5 mol / l aqueous solution of nickel sulfate was prepared, and ion exchange water or sulfuric acid was added to the aqueous nickel sulfate solution to adjust the pH to 0.5 to p.
A nickel sulfate aqueous solution up to H6 was prepared. 300 g of the same hydrogen storage alloy powder as in Example 1 was immersed in 500 ml of each of these nickel sulfate aqueous solutions, and stirred at room temperature for about 1 hour to prepare a hydrogen storage alloy powder for a negative electrode. A battery was produced in the same manner as in Example 1 using these hydrogen storage alloy powders. Table 3 shows the results of evaluating these batteries under the same conditions as described above. If the pH is too high, the effect of etching the metal to be dissolved from the surface is reduced, so the pH of the acidic aqueous solution used for the treatment is desirably 4 or less. Although the same type of acid is added here to change the pH of the acidic aqueous solution, another acid such as nitric acid may be added.
【００３６】[0036]
【表３】 [Table 3]
【００３７】《実施例１０》実施例１と同様の方法で水
素吸蔵合金を作製し、粉末の状態では処理を行わないで
実施例１記載の要領で水素吸蔵合金電極を作製した。
１．５ｍｏｌ／ｌの硫酸ニッケル水溶液を調製し、この
硫酸ニッケル水溶液２０００ｍｌ中に前記水素吸蔵合金
電極を室温で約１時間浸漬処理した。この電極を用いて
実施例１と同様にして電池を作製し、評価した。この電
池のサイクル寿命は１１００サイクル、高率放電特性は
９５％を示し、実施例１と同等の性能であった。したが
って、水素吸蔵合金粉末をＮｉ2+イオンを含有する酸性
水溶液で浸漬処理しても、水素吸蔵合金電極の作成後浸
漬処理しても本発明の効果は有効である。Example 10 A hydrogen-absorbing alloy was produced in the same manner as in Example 1, and a hydrogen-absorbing alloy electrode was produced in the manner described in Example 1 without any treatment in the powder state.
A 1.5 mol / l nickel sulfate aqueous solution was prepared, and the hydrogen storage alloy electrode was immersed in 2000 ml of the nickel sulfate aqueous solution at room temperature for about 1 hour. Using this electrode, a battery was fabricated and evaluated in the same manner as in Example 1. The cycle life of this battery was 1,100 cycles, and the high rate discharge characteristics were 95%, which was equivalent to that of Example 1. Therefore, the effects of the present invention are effective regardless of whether the hydrogen storage alloy powder is immersed in an acidic aqueous solution containing Ni 2+ ions or immersed after the preparation of the hydrogen storage alloy electrode.
【００３８】なお、上記の実施例中では、酸性水溶液中
での浸漬処理について、すべて室温で処理した場合につ
いて説明したが、酸性水溶液の温度を１０〜９０℃の温
度で試したところ、実施例と同様の効果が得られた。温
度が高いほど水素吸蔵合金粉末の表面が浸食されやすい
ので、処理温度が高い場合には処理時間を短くすること
ができる。また、本発明は酸性水溶液で水素吸蔵合金粉
末を処理するため、処理後に水洗することが望ましい。
ただし、水洗しないで電池構成した場合でもアルカリ電
解液と反応するが、大きな電池性能の低下はない。上記
の実施例では、代表例としてＮｉ2+イオンを含む処理液
について説明したが、水素吸蔵合金粉末の表面に多くし
たい金属イオンを含有する酸性水溶液で水素吸蔵合金粉
末を浸漬処理することにより、水素吸蔵合金粉末の表面
に特定金属リッチな表面層を作製することができる。ま
た、この処理方法は、実施例以外の組成を持つ水素吸蔵
合金に対しても有効であり、たとえば、ＡＢ5型水素吸
蔵合金の場合、Ｍｍ、Ｎｉ、Ｍｎ、Ａｌ、Ｃｏ、Ｆｅ、
Ｃｒ、Ｃｕ、Ｚｒ、Ｔｉ、Ｂなどを含んでいてもよい。
また、水素吸蔵合金はＡＢ5型の他、ＡＢ2型、ＡＢ型、
Ａ2Ｂ型、その他の固溶体系の水素吸蔵合金でも本発明
の方法で、特定の金属リッチな水素吸蔵合金粉末表面を
作製することができる。In the above examples, all the immersion treatments in an acidic aqueous solution were described as being performed at room temperature, but when the temperature of the acidic aqueous solution was tested at a temperature of 10 to 90 ° C. The same effect as described above was obtained. The higher the temperature, the more easily the surface of the hydrogen-absorbing alloy powder is eroded, so that when the processing temperature is high, the processing time can be shortened. In the present invention, since the hydrogen storage alloy powder is treated with an acidic aqueous solution, it is desirable to wash the powder after the treatment.
However, even when the battery is configured without washing with water, it reacts with the alkaline electrolyte, but there is no significant decrease in battery performance. In the above embodiment, the treatment liquid containing Ni 2+ ions was described as a representative example.However, by immersing the hydrogen storage alloy powder in an acidic aqueous solution containing a metal ion to be increased on the surface of the hydrogen storage alloy powder, A specific metal-rich surface layer can be formed on the surface of the hydrogen storage alloy powder. Also, this treatment method is also effective for the hydrogen storage alloy having a composition other than the Examples, for example, the case of AB 5 -type hydrogen absorbing alloy, Mm, Ni, Mn, Al , Co, Fe,
It may contain Cr, Cu, Zr, Ti, B, and the like.
Another hydrogen storage alloy type 5 AB, AB 2 type, AB type,
With the method of the present invention, a specific metal-rich hydrogen-absorbing alloy powder surface can also be produced by using the A 2 B type or other solid-solution type hydrogen-absorbing alloy by the method of the present invention.
【００３９】[0039]
【発明の効果】以上のように本発明によれば、特定の金
属リッチな表面を有する水素吸蔵合金粉末とすることが
可能であり、その金属種によって、耐食性の向上や初期
活性の向上などのメリットを持った水素吸蔵合金電極と
することができる。そして、処理液として、例えばＮｉ
2+イオンを含有している酸性水溶液を用いると、長寿命
で高率放電特性に優れるニッケル・水素蓄電池を与える
水素吸蔵合金電極を提供することができる。As described above, according to the present invention, it is possible to obtain a hydrogen-absorbing alloy powder having a specific metal-rich surface. Depending on the type of the metal, it is possible to improve the corrosion resistance and the initial activity. A hydrogen storage alloy electrode having advantages can be obtained. Then, as the treatment liquid, for example, Ni
When an acidic aqueous solution containing 2+ ions is used, a hydrogen storage alloy electrode that provides a nickel-hydrogen storage battery having a long life and excellent high-rate discharge characteristics can be provided.
【図１】本発明の一実施例における密閉式電池の概略構
成を示す縦断面図である。FIG. 1 is a longitudinal sectional view showing a schematic configuration of a sealed battery according to one embodiment of the present invention.
１ セパレータ ２ 負極 ３ 正極 ４ 負極端子 ５ ケース ６ 安全弁 ７ 封口板 ８ Ｏリング ９ ナット DESCRIPTION OF SYMBOLS 1 Separator 2 Negative electrode 3 Positive electrode 4 Negative terminal 5 Case 6 Safety valve 7 Sealing plate 8 O-ring 9 Nut
───────────────────────────────────────────────────── フロントページの続き (72)発明者 湯淺 真一 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 (72)発明者 生駒 宗久 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shinichi Yuasa 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.
Claims (5)
金を構成する少なくとも１種の金属のイオンを含有して
いる酸性水溶液中に浸漬処理する工程、および前記処理
を経た水素吸蔵合金粉末を用いて電極を作成する工程を
有することを特徴とする水素吸蔵合金電極の製造方法。1. A step of immersing a powder of a hydrogen storage alloy in an acidic aqueous solution containing ions of at least one metal constituting the hydrogen storage alloy. A method for producing a hydrogen-absorbing alloy electrode, comprising a step of forming an electrode using the electrode.
求項１記載の水素吸蔵合金電極の製造方法。2. The method according to claim 1, wherein the metal ions are Ni 2+ ions.
粉末からなる電極を、Ｎｉ2+イオンを含有している酸性
水溶液中に浸漬処理する工程を有することを特徴とする
水素吸蔵合金電極の製造方法。3. A hydrogen storage alloy electrode comprising a step of immersing an electrode made of a powder of a hydrogen storage alloy containing nickel as one component in an acidic aqueous solution containing Ni 2+ ions. Production method.
度の２０％以上の濃度である請求項２または３記載の水
素吸蔵合金電極の製造方法。4. The method for producing a hydrogen storage alloy electrode according to claim 2, wherein the concentration of Ni 2+ ions in the acidic aqueous solution is 20% or more of the saturation concentration.
２または３記載の水素吸蔵合金電極の製造方法。5. The method for producing a hydrogen storage alloy electrode according to claim 2, wherein the pH of the acidic aqueous solution is 4 or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8308938A JPH10149824A (en) | 1996-11-20 | 1996-11-20 | Manufacture of hydrogen storage alloy electrode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8308938A JPH10149824A (en) | 1996-11-20 | 1996-11-20 | Manufacture of hydrogen storage alloy electrode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10149824A true JPH10149824A (en) | 1998-06-02 |
Family
ID=17987081
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8308938A Pending JPH10149824A (en) | 1996-11-20 | 1996-11-20 | Manufacture of hydrogen storage alloy electrode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10149824A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10255779A (en) * | 1997-03-14 | 1998-09-25 | Toshiba Corp | Manufacture for nickel hydrogen storage battery |
| WO1999066573A1 (en) * | 1998-06-18 | 1999-12-23 | Sanyo Electric Co., Ltd. | Hydrogen absorbing alloy for alkaline storage battery and method for production thereof, and hydrogen absorbing alloy electrode for alkaline storage battery and method for production thereof |
| WO2000001023A1 (en) * | 1998-06-26 | 2000-01-06 | Sanyo Electric Co., Ltd. | Hydrogen absorbing alloy for alkaline storage battery and method for preparing the same |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08291391A (en) * | 1995-02-22 | 1996-11-05 | Toyota Central Res & Dev Lab Inc | Surface treatment of hydrogen occlusion alloy material, activation treatment of hydrogen occlusion alloy electrode, activating solution, and hydrogen occlusion alloy electrode having excellent initial activity |
| JPH1012233A (en) * | 1996-06-26 | 1998-01-16 | Sanyo Electric Co Ltd | Manufacture of hydrogen storage alloy for alkaline storage battery |
| JPH1021907A (en) * | 1996-07-01 | 1998-01-23 | Chuo Denki Kogyo Kk | Manufacture of hydrogen storage alloy powder, and ni-hydrogen battery |
-
1996
- 1996-11-20 JP JP8308938A patent/JPH10149824A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08291391A (en) * | 1995-02-22 | 1996-11-05 | Toyota Central Res & Dev Lab Inc | Surface treatment of hydrogen occlusion alloy material, activation treatment of hydrogen occlusion alloy electrode, activating solution, and hydrogen occlusion alloy electrode having excellent initial activity |
| JPH1012233A (en) * | 1996-06-26 | 1998-01-16 | Sanyo Electric Co Ltd | Manufacture of hydrogen storage alloy for alkaline storage battery |
| JPH1021907A (en) * | 1996-07-01 | 1998-01-23 | Chuo Denki Kogyo Kk | Manufacture of hydrogen storage alloy powder, and ni-hydrogen battery |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10255779A (en) * | 1997-03-14 | 1998-09-25 | Toshiba Corp | Manufacture for nickel hydrogen storage battery |
| WO1999066573A1 (en) * | 1998-06-18 | 1999-12-23 | Sanyo Electric Co., Ltd. | Hydrogen absorbing alloy for alkaline storage battery and method for production thereof, and hydrogen absorbing alloy electrode for alkaline storage battery and method for production thereof |
| WO2000001023A1 (en) * | 1998-06-26 | 2000-01-06 | Sanyo Electric Co., Ltd. | Hydrogen absorbing alloy for alkaline storage battery and method for preparing the same |
| US6576367B1 (en) | 1998-06-26 | 2003-06-10 | Sanyo Electric Co., Ltd. | Hydrogen storage alloy for use in alkaline storage batteries and method for production thereof |
| US7078126B2 (en) | 1998-06-26 | 2006-07-18 | Sanyo Electric Co., Ltd. | Method for production of hydrogen storage alloy for use in alkaline storage batteries |
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