JPH11116201A - Hydrogen storage device and hydrogen occlusion alloy electrode and their production - Google Patents
Hydrogen storage device and hydrogen occlusion alloy electrode and their productionInfo
- Publication number
- JPH11116201A JPH11116201A JP9288529A JP28852997A JPH11116201A JP H11116201 A JPH11116201 A JP H11116201A JP 9288529 A JP9288529 A JP 9288529A JP 28852997 A JP28852997 A JP 28852997A JP H11116201 A JPH11116201 A JP H11116201A
- Authority
- JP
- Japan
- Prior art keywords
- hydrogen storage
- hydrogen
- powder
- storage alloy
- flake
- 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
- 239000001257 hydrogen Substances 0.000 title claims abstract description 122
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 122
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 116
- 238000003860 storage Methods 0.000 title claims abstract description 90
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 80
- 239000000956 alloy Substances 0.000 title claims abstract description 80
- 238000004519 manufacturing process Methods 0.000 title claims description 18
- 239000000843 powder Substances 0.000 claims abstract description 83
- 229910052751 metal Inorganic materials 0.000 claims abstract description 36
- 239000002184 metal Substances 0.000 claims abstract description 35
- 238000000034 method Methods 0.000 claims abstract description 18
- 238000002156 mixing Methods 0.000 claims abstract description 10
- 229910000765 intermetallic Inorganic materials 0.000 claims description 8
- 238000000227 grinding Methods 0.000 claims description 7
- 230000000694 effects Effects 0.000 claims description 6
- 150000002431 hydrogen Chemical class 0.000 claims description 6
- 239000012798 spherical particle Substances 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 6
- 230000004913 activation Effects 0.000 description 5
- 239000011230 binding agent Substances 0.000 description 5
- 238000005096 rolling process Methods 0.000 description 5
- 150000002739 metals Chemical class 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000010791 quenching Methods 0.000 description 3
- 230000000171 quenching effect Effects 0.000 description 3
- 229910019582 Cr V Inorganic materials 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000009689 gas atomisation Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910018007 MmNi Inorganic materials 0.000 description 1
- 229910010389 TiMn Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910000756 V alloy Inorganic materials 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000010191 image analysis Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- BFDHFSHZJLFAMC-UHFFFAOYSA-L nickel(ii) hydroxide Chemical compound [OH-].[OH-].[Ni+2] BFDHFSHZJLFAMC-UHFFFAOYSA-L 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000011232 storage material Substances 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 238000003466 welding Methods 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
-
- 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
- Y02E60/30—Hydrogen technology
- Y02E60/32—Hydrogen storage
Landscapes
- Hydrogen, Water And Hydrids (AREA)
- Powder Metallurgy (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
- Manufacture Of Metal Powder And Suspensions Thereof (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、水素貯蔵装置およ
び水素吸蔵合金電極並びにそれらの製造方法に関し、特
にフレーク状の水素吸蔵合金にフレーク状の金属粉末を
混合することによって、貯蔵装置としての水素の充填時
間の短縮および水素電極としての高率放電特性に優れた
水素貯蔵装置および水素吸蔵合金電極並びにそれらの製
造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogen storage device, a hydrogen storage alloy electrode, and a method for producing the same. More particularly, the present invention relates to a hydrogen storage device comprising a flake-shaped metal powder mixed with a flake-shaped hydrogen storage alloy. TECHNICAL FIELD The present invention relates to a hydrogen storage device, a hydrogen storage alloy electrode, and a method for producing the hydrogen storage device, which have a reduced filling time and excellent high-rate discharge characteristics as a hydrogen electrode.
【０００２】[0002]
【従来の技術】水素の貯蔵・輸送手段として、水素吸蔵
合金は、合金自身の体積の約1000倍以上の水素ガスを吸
蔵し貯蔵することが可能であり、その体積密度は、液体
あるいは固体水素とほぼ同等かあるいはそれ以上であ
る。この水素吸蔵材料として、Ｖ，Ｎｂ，ＴａやＴｉ−
Ｖ合金などの体心立方構造（以下ＢＣＣ構造と呼称す
る）の金属は、すでに実用化されているＬａＮｉ5 など
のＡＢ5 型合金やＴｉＭｎ2などのＡＢ2 型合金に比
べ、大量の水素を吸蔵することは古くから知られてい
た。このように、ＢＣＣ構造では、その結晶格子中の水
素吸蔵サイトが多く、計算による水素吸蔵量がＨ／Ｍ＝
２．０（原子量５０程度のＴｉやＶなど合金では約４．
０wt％）と極めて大きいためである。2. Description of the Related Art As a means for storing and transporting hydrogen, a hydrogen storage alloy can store and store hydrogen gas of about 1000 times or more the volume of the alloy itself, and its volume density is liquid or solid hydrogen. It is almost the same or more. As this hydrogen storage material, V, Nb, Ta, Ti-
Metals having a body-centered cubic structure (hereinafter, referred to as a BCC structure) such as V alloys generate a larger amount of hydrogen than AB 5 type alloys such as LaNi 5 or AB 2 type alloys such as TiMn 2 which are already in practical use. Occlusion has been known for a long time. As described above, in the BCC structure, the number of hydrogen storage sites in the crystal lattice is large, and the calculated hydrogen storage amount is H / M =
2.0 (approximately 4.
(0% by weight).
【０００３】一方、例えばニッケル−水素電池におい
て、負極としての水素吸蔵合金では、実用時に繰り返し
行われる充放電サイクルによって、大きなヒステリヒス
が発生しないように合金自体の耐久性を向上し、かつ初
期放電特性の改善が重要となる。 この分野の公知技術
として、例えば特開平４−２６２３６７号および特開昭
６０−１７２１６６号公報には、フレーク状のニッケル
と、水素吸蔵合金粉末を混合して成形した水素吸蔵合金
電極が開示されている。この時、ニッケルをフレーク状
とすることで、水素吸蔵合金の電気伝導性が改善される
ことが記載されている。これらの公知技術では、電導性
を向上させるには、隙間をできるだけ小さくし、また接
触面積を大きくすることが重要であることの開示に止ま
っている。On the other hand, for example, in a nickel-hydrogen battery, with a hydrogen storage alloy as a negative electrode, the durability of the alloy itself is improved so that large hysteresis is not generated by repeated charge / discharge cycles during practical use, and the initial discharge characteristics are improved. Improvement is important. As a known technique in this field, for example, JP-A-4-26267 and JP-A-60-172166 disclose a hydrogen storage alloy electrode formed by mixing flake nickel and a hydrogen storage alloy powder. I have. At this time, it is described that the electrical conductivity of the hydrogen storage alloy is improved by forming nickel into flakes. These known techniques only disclose that it is important to reduce the gap as much as possible and increase the contact area in order to improve the conductivity.
【０００４】また、水素貯蔵装置（タンク）としては、
例えば特開平９−４９００２号公報に、熱伝導性の低い
チタン系水素吸蔵合金粉末に、熱伝導性のよい銅粉末を
混合充填し、熱伝導性を改良して水素吸放出速度を改善
することが記載されている。この場合でも、より熱伝導
性を上げるには、隙間をなくし、接触面積を大きくする
ことが必要とされている。粉末の形状については、従来
急冷方法の１つとして、フレーク状粉末が得られるロー
ル急冷法の提案はあるとはいえ、粉末形状とこのような
電極としての特性との関係について言及したものはな
い。そこで、水素吸蔵合金においては、水素吸蔵装置と
しての熱伝導性および電極としての電気伝導性のさらな
る改善が望まれ、そのための粉末の形状との関係から、
製造コストおよび電極の耐久性を含め特性に優れた水素
吸蔵合金粉末およびこの製造方法の技術開発が望まれて
いる。[0004] As a hydrogen storage device (tank),
For example, Japanese Patent Application Laid-Open No. 9-49002 discloses that a titanium-based hydrogen storage alloy powder having a low thermal conductivity is mixed and filled with a copper powder having a good thermal conductivity to improve the thermal conductivity and improve the hydrogen absorption / desorption rate. Is described. Even in this case, in order to further increase the thermal conductivity, it is necessary to eliminate the gap and increase the contact area. Regarding the shape of the powder, although there is a proposal of a roll quenching method that can obtain flake-like powder as one of the conventional quenching methods, there is no mention of the relationship between the powder shape and such characteristics as an electrode. . Therefore, in the hydrogen storage alloy, it is desired to further improve the thermal conductivity as a hydrogen storage device and the electrical conductivity as an electrode, from the relationship with the powder shape for that,
There is a need for a hydrogen storage alloy powder excellent in characteristics including production cost and electrode durability, and technical development of this production method.
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は、水素
吸蔵合金の形状を検討し、その充填率を向上し接触面積
を拡大して熱・電気の良伝導体とすることを可能とする
水素貯蔵装置および水素吸蔵合金電極並びにそれらの製
造方法を提供することにある。また、本発明の他の目的
は、従来の通常粉とフレーク粉の混合より前記空隙を低
減する方法を検討し、無秩序充填に際して比表面積を増
大できる形状とした粉末によって水素貯蔵装置および水
素吸蔵合金電極並びにそれらの製造方法を提供すること
にある。SUMMARY OF THE INVENTION It is an object of the present invention to examine the shape of a hydrogen storage alloy, improve its filling rate and enlarge the contact area to make it a good conductor of heat and electricity. An object of the present invention is to provide a hydrogen storage device, a hydrogen storage alloy electrode, and a method for producing the same. Another object of the present invention is to examine a method for reducing the voids by mixing conventional ordinary powder and flake powder, and to use a hydrogen storage device and a hydrogen storage alloy by using a powder that can increase the specific surface area during random filling. An object of the present invention is to provide an electrode and a method for manufacturing the electrode.
【０００６】さらに、本発明の別の目的は、水素吸蔵合
金の粉末の簡便にして大量製造に適した製造方法を検討
し、フレーク粉（片状粒、鱗片粒）として、かつ粉末内
部に加工による歪みを残留させた粉末による水素貯蔵装
置および水素吸蔵合金電極並びにそれらの製造方法を提
供することにある。Another object of the present invention is to examine a method for producing hydrogen storage alloy powder which is simple and suitable for mass production, and to process it as flake powder (flakes, scales) and inside the powder. It is an object of the present invention to provide a hydrogen storage device, a hydrogen storage alloy electrode, and a method for producing the same using powder having residual strain due to hydrogen.
【０００７】[0007]
【課題を解決するための手段】上記の目的は、水素を吸
放出するための水素貯蔵装置であって、フレーク状の水
素吸蔵合金粉末と、フレーク状の他の金属粉末とが均一
に混合されてなることを特徴とする水素貯蔵装置によっ
て達成される。また、上記の目的は、前記他の金属粉末
が水素吸蔵合金より熱伝導性の高い金属からなることを
特徴とする前記水素貯蔵装置によっても達成される。さ
らに、上記の目的は、前記水素吸蔵合金と他の金属粉末
の表面性状として、ともに凹凸度合いが４以下であっ
て、かつ他の金属粉末と水素吸蔵合金粉末の平均直径の
比が０．６以下であることを特徴とする前記水素貯蔵装
置によっても達成される。SUMMARY OF THE INVENTION An object of the present invention is to provide a hydrogen storage device for absorbing and releasing hydrogen, wherein a flake-shaped hydrogen storage alloy powder and another flake-shaped metal powder are uniformly mixed. This is achieved by a hydrogen storage device characterized by the following. Further, the above object is also achieved by the hydrogen storage device, wherein the other metal powder is made of a metal having higher thermal conductivity than a hydrogen storage alloy. In addition, the above object is achieved in that the surface properties of the hydrogen storage alloy and the other metal powder both have a degree of irregularity of 4 or less, and the ratio of the average diameter of the other metal powder to the hydrogen storage alloy powder is 0.6. This is also achieved by the hydrogen storage device described below.
【０００８】また、上記の目的は、水素電極の材料であ
って、フレーク状の水素吸蔵合金粉末と、フレーク状の
他の金属粉末とが均一に混合されてなることを特徴とす
る水素吸蔵合金電極によっても達成される。さらに、上
記の目的は、前記他の金属粉末が水素吸蔵合金より電気
伝導性の高い金属からなることを特徴とする前記水素吸
蔵合金電極によっても達成される。また、上記の目的
は、前記水素吸蔵合金と他の金属粉末の表面性状とし
て、ともに凹凸度合いが４以下であって、かつ他の金属
粉末と水素吸蔵合金粉末の平均直径の比が０．６以下で
あることを特徴とする前記水素貯蔵装置によっても達成
される。Another object of the present invention is to provide a hydrogen storage alloy which is a material for a hydrogen electrode, wherein a flake-shaped hydrogen storage alloy powder and another flake-shaped metal powder are uniformly mixed. It is also achieved by electrodes. Further, the above object is also achieved by the hydrogen storage alloy electrode, wherein the other metal powder is made of a metal having higher electrical conductivity than the hydrogen storage alloy. In addition, the above-mentioned object is achieved in that the surface properties of the hydrogen storage alloy and the other metal powder both have an unevenness degree of 4 or less, and the ratio of the average diameter of the other metal powder and the hydrogen storage alloy powder is 0.6. This is also achieved by the hydrogen storage device described below.
【０００９】さらに、上記の目的は、水素を吸放出する
ための水素貯蔵装置の製造方法であって、ＢＣＣ相（体
心立方）を主相とし、少量の金属間化合物相が均一に分
布したＢＣＣ水素吸蔵合金を、摩砕効果を付与する粉砕
機で擬球形粒子からなる合金粉末とする工程と、さらに
機械的圧力を加えてフレーク状とする工程と、前記合金
粉末とフレーク状の他の金属粉末とを混合する工程とを
有することを特徴とする前記水素貯蔵装置の製造方法に
よっても達成される。また、上記の目的は、水素電極の
製造方法であって、ＢＣＣ相（体心立方）を主相とし、
少量の金属間化合物相が均一に分布したＢＣＣ水素吸蔵
合金を、摩砕効果を付与する粉砕機で擬球形粒子からな
る合金粉末とする工程と、さらに機械的圧力を加えてフ
レーク状とする工程と、前記合金粉末とフレーク状の他
の金属粉末とを混合する工程とを有することを特徴とす
る前記水素吸蔵合金電極の製造方法によっても達成され
る。Further, the above-mentioned object is a method of manufacturing a hydrogen storage device for absorbing and releasing hydrogen, wherein a BCC phase (body-centered cubic) is a main phase and a small amount of an intermetallic compound phase is uniformly distributed. A step of converting the BCC hydrogen-absorbing alloy into an alloy powder composed of pseudo-spherical particles with a pulverizer that imparts a grinding effect, a step of further applying mechanical pressure to form a flake, And a step of mixing with a metal powder. The above object is a method for producing a hydrogen electrode, wherein a BCC phase (body-centered cubic) is a main phase,
A step of converting a BCC hydrogen storage alloy in which a small amount of an intermetallic compound phase is uniformly distributed into an alloy powder composed of pseudo-spherical particles using a pulverizer that imparts a grinding effect, and further forming a flake by applying mechanical pressure. And a step of mixing the alloy powder and other metal powder in the form of flakes, which is also achieved by the method for producing a hydrogen storage alloy electrode.
【００１０】[0010]
【発明の実施の形態】本発明では、フレーク粉同士を混
合してあるので、隙間が小さく、また接触面積も大きい
ので、特性が向上する。また、その際、凹凸度合を特定
の範囲に規定することで、フレーク粉同士の隙間があま
り生じない。また、ＢＣＣの水素吸蔵合金を用いる場
合、合金塊からフレーク状にしようとすると、延性が高
いため粉砕が困難である。そこで、多少金属間化合物を
分散させ、それを一旦摩砕により擬似的な球形の粒子に
し、その後圧延等によりフレーク状とすることで、延性
の高いＢＣＣ水素吸蔵合金でもフレーク状とすることが
できる。さらに、本発明の請求項７または８に係る水素
吸蔵合金を用いると、粉末内部の歪みにより初期活性が
向上する。また、必要に応じて圧粉体または焼結体とし
て用いることができる。BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, since flake powder is mixed, the gap is small and the contact area is large, so that the characteristics are improved. Also, in this case, by defining the degree of unevenness in a specific range, a gap between the flake powders does not occur much. In addition, when a hydrogen storage alloy of BCC is used, it is difficult to pulverize the alloy lumps because the ductility is high when the alloy flakes are formed. Therefore, by slightly dispersing the intermetallic compound, milling it into pseudo-spherical particles once, and then forming it into a flake shape by rolling or the like, it is possible to make even a highly ductile BCC hydrogen storage alloy into a flake shape. . Further, when the hydrogen storage alloy according to claim 7 or 8 of the present invention is used, the initial activity is improved due to the strain inside the powder. Further, it can be used as a green compact or a sintered body as required.
【００１１】本発明の水素吸蔵合金とは、ＢＣＣ相（体
心立方）を主相とし、少量の金属間化合物相が均一に分
布したＢＣＣ水素吸蔵合金であればよく、例えばＴｉ−
Ｖ系、Ｔｉ−Ｖ−Ｍｎ系、Ｔｉ−Ｖ−Ｍｎ−Ｃｒ系、Ｔ
ｉ−Ｃｒ−Ｖ系並びにＴｉ−Ｃｒ−Ｖ系を基本として他
の金属元素を含有した合金を挙げることができる。熱伝
導性に優れた他の金属としては、例えばＣｕ、Ａｌ等を
主たる成分とするものであり、電気伝導性の優れた金属
としては、例えばＮｉ、Ｃｕ等を挙げることができる。The hydrogen storage alloy of the present invention may be any BCC hydrogen storage alloy having a BCC phase (body-centered cubic) as a main phase and a small amount of an intermetallic compound phase uniformly distributed.
V-based, Ti-V-Mn-based, Ti-V-Mn-Cr-based, T
Alloys containing other metal elements based on i-Cr-V and Ti-Cr-V can be given. Other metals having excellent thermal conductivity include, for example, Cu, Al and the like as main components, and metals having excellent electrical conductivity include, for example, Ni and Cu.
【００１２】本発明によれば、フレーク粉同士の接触と
なり、接触面積が拡大して熱・電気の伝導性が向上す
る。さらに、水素貯蔵容器としては熱伝導性の向上によ
り、外部との熱交換特性が改善され水素充填時間が短縮
することになる。また、水素吸蔵合金電極としては、電
気伝導性の向上し電池内部抵抗の減少により高率放電特
性改善が可能となる。これは、主として通常粉とフレー
ク粉の混合時に比べ空隙が低減して単位体積あたりの充
填率が向上するためである。さらに、クレーム５の方法
で製造したフレーク状水素吸蔵合金を用いる場合、粉末
内部に圧延時の歪みが蓄積されているため、初期活性化
特性が向上する。また、凹凸度合いとは、画像解析によ
りフレーク粉を上方から２次元的に観察した値として下
記のように定義される。According to the present invention, the flake powder comes into contact with each other, the contact area is increased, and the heat and electricity conductivity is improved. Further, the heat conductivity of the hydrogen storage container is improved, so that the heat exchange characteristic with the outside is improved, and the hydrogen filling time is shortened. Further, as the hydrogen storage alloy electrode, it is possible to improve the electrical conductivity and reduce the internal resistance of the battery to improve the high rate discharge characteristics. This is mainly because the voids are reduced and the packing ratio per unit volume is improved as compared with the case where the normal powder and the flake powder are mixed. Furthermore, in the case of using the flake-form hydrogen storage alloy produced by the method of claim 5, the initial activation characteristics are improved because strain during rolling is accumulated inside the powder. The degree of unevenness is defined as follows as a value obtained by two-dimensionally observing flake powder from above by image analysis.
【００１３】（凹凸度合い）＝（凹凸を有する形状の周
長の二乗）／（凹凸を有する形状の面積・４π） また、金型成形を行う場合においては、フレーク粉の向
きを揃える目的で振動充填を行うことが好ましい。この
ように定義される前記凹凸度合いが４を超えるようなフ
レーク粉の場合、混粉時にフレーク粉同士が絡み合って
凝集し、均一に混合できないばかりでなく、容器や金型
などへの充填性が低下する。また、フレーク状金属粉末
と水素吸蔵合金粉末の平均直径の比が０．６を超えると
フレーク粉同士の隙間が増加して混合粉の嵩密度や圧粉
体密度が低下し、十分な効果が得られない。同様の理由
で、フレーク状金属粉末の混合率は１０〜５０ｗｔ％
（１０〜３０ｖｆ％）が適当である。(Degree of unevenness) = (square of the circumference of the shape having unevenness) / (area of the shape having unevenness · 4π) Further, in the case of molding, vibration is applied to align the direction of the flake powder. Preferably, filling is performed. In the case of the flake powder having the degree of unevenness defined as above exceeding 4, the flake powder is entangled and agglomerated at the time of mixing, not only cannot be uniformly mixed, but also has a good filling property into a container or a mold. descend. Also, if the ratio of the average diameter of the flake-like metal powder and the hydrogen storage alloy powder exceeds 0.6, the gap between the flake powders increases, and the bulk density and green compact density of the mixed powder decrease. I can't get it. For the same reason, the mixing ratio of the flake-like metal powder is 10 to 50 wt%.
(10 to 30 vf%) is appropriate.
【００１４】なお、平均直径とは、同一面積の円の直径
に換算したもので、水素吸蔵合金とその他の金属につい
てこの直径を求めたものである。また、フレーク粉の製
造方法は特に限定されるものではなく、例えば回転ディ
スクへの不活性ガスアトマイズ法、ロール急冷法により
製造したリボンまたはフレークの粉砕する方法、または
不活性ガスアトマイズ法によって製造した球状粉または
摩砕効果の高い粉砕機によって、製造した擬球形粉末の
圧延（スタンピング）法等がある。この内、擬球形粉末
の圧延について金属間化合物は脆く、通常では圧延でき
ないが、完全なＢＣＣ固溶体では延性が高く粉砕が困難
であるため本発明第７発明の方法を用いて初めて、「粉
砕＋圧延」工程として成立する。さらに、必要によって
介在物の量や分布形状は組成および熱処理条件によって
制御してもよい。以下に、本発明について実施例によっ
てさらに詳述する。The average diameter is converted into the diameter of a circle having the same area, and the diameter is obtained for a hydrogen storage alloy and other metals. The method of producing the flake powder is not particularly limited, for example, an inert gas atomizing method for a rotating disk, a method of crushing a ribbon or flake produced by a roll quenching method, or a spherical powder produced by an inert gas atomizing method. Alternatively, there is a method of rolling (stamping) the pseudo-spherical powder produced by a pulverizer having a high grinding effect. Among these, the intermetallic compound is brittle and cannot be rolled normally in the rolling of pseudo-spherical powder, but the complete BCC solid solution has high ductility and is difficult to be crushed. This is established as a "rolling" step. Further, if necessary, the amount and distribution shape of the inclusions may be controlled by the composition and the heat treatment conditions. Hereinafter, the present invention will be described in more detail with reference to Examples.
【００１５】[0015]
【実施例】本発明の実施例として、表１および表２に示
されるように、水素吸蔵合金としてMmNi3.55Co0.75Mn
0.4Al0.3およびTi25Cr35V40 について、バインダとして
記載してある他の金属粉末としてNiおよびCuのフレーク
状および粒状を使用して水素吸蔵装置および電極として
の特性を試験した。EXAMPLES As an example of the present invention, as shown in Tables 1 and 2, MmNi 3.55 Co 0.75 Mn was used as a hydrogen storage alloy.
0.4 Al 0.3 and Ti 25 Cr 35 V 40 were tested for hydrogen storage and electrode properties using Ni and Cu flakes and granules as other metal powders described as binders.
【００１６】[0016]
【表１】 [Table 1]
【００１７】[0017]
【表２】 [Table 2]
【００１８】本実施例の水素吸蔵合金粉末は、全て少し
の金属間化合物を分散させ、摩砕効果の高い粉砕機とし
て、ボールミル（またはロッドミル）によって擬球状に
して、その後スタンプミルによってフレーク状とした。
また、充填率は圧粉体空隙率として表示した値で示し
た。この充填状態は、図３（ａ）および（ｂ）に示めす
ように、発明例では空隙率が少なく図３（ａ）の状態で
あるが、例えば従来の隙間の大きい状態は図３（ｂ）と
して示される。さらに、電気自動車用電池としての実用
性から、充電：５０ｍＡ／ｇ×７時間（２５℃）として
の容量試験を行った結果について図１に示す。図１で
は、−２００meshの水素吸蔵合金粉末０．２ｇとバイン
ダー（Ｎｉ粉）０．８ｇを乳鉢で混合し（比較例１はバ
インダー混合なし）、金型成形により面圧５ ton／cm2
の圧力で直径１０mmのペレットに成形し、これを２枚の
発泡Ｎｉで挟んで再プレスしたものにＮｉ箔（リード）
を抵抗溶接し評価電極とした。正極には負極容量の１０
倍以上の焼結式水酸化ニッケルを用いて負極規制とし電
解液に６Ｎ水酸化カリウムを用いて下記の条件で充放電
試験を実施した。 充電 ：５０ｍＡ／ｇ（ＭＨ）×７ｈ（２５℃） 放電 ：５０，３００，６００ｍＡ／ｇ（２５℃） 終止電圧：両極間電位差＝１Ｖ 図１から、発明例１では、比較例１および２に比較し
て、放電電流の増加につれて放電容量の減少量が小さ
く、単位重量または単位体積当たりの放電容量が大きい
ことを示している。なお、表２には、単位：ｍＡｈ／ｇ
で示しているが、発明例は比較例よりも放電容量が大き
いことがわかる。水素吸蔵装置として水素吸蔵特性につ
いては、水素加圧の活性化処理の後、水素吸蔵量として
容積法による圧力組成等温測定法によって、時間との関
係を求めた。図２では、−４０meshの水素吸蔵合金粉末
２４００ｇとバインダー（Ｎｉ粉）６００ｇをＶ型混粉
機で混合し（比較例５はバインダー混合なし）、プレー
トフィン構造をもつ容積約１リットルの円筒型密閉容器
に充填し、下記条件で十分活性化処理を行った時の水素
充填特性を評価した。 活性化；真空引き×１ｈ（６０℃）→水素加圧１０kg／
cm2G（０℃）の繰り返し（図２のグラフは１０サイクル
目の結果） 図２に発明例５および比較例５および６について、時間
と水素吸蔵量の関係を示す。発明例においては、約５分
でほぼ１００％の水素吸蔵量を示すが、比較例では１０
ないし２０分を要している。The hydrogen-absorbing alloy powder of the present embodiment has a small amount of intermetallic compound dispersed therein and is made into a pseudo-spherical shape by a ball mill (or a rod mill) as a pulverizer having a high grinding effect. did.
The filling rate was indicated by a value indicated as a porosity of the green compact. As shown in FIGS. 3 (a) and 3 (b), this filling state is the state of FIG. 3 (a) in which the porosity is small in the example of the present invention. ). Further, from the practicality as a battery for an electric vehicle, FIG. 1 shows a result of a capacity test performed with charging: 50 mA / g × 7 hours (25 ° C.). In FIG. 1, 0.2 g of a hydrogen storage alloy powder of -200 mesh and 0.8 g of a binder (Ni powder) were mixed in a mortar (in Comparative Example 1, no binder was mixed), and the surface pressure was 5 ton / cm 2 by die molding.
Into a pellet having a diameter of 10 mm under the following pressure, sandwiched between two pieces of foamed Ni, and pressed again to form a Ni foil (lead).
Was used as an evaluation electrode by resistance welding. The positive electrode has a negative electrode capacity of 10
The charge / discharge test was carried out under the following conditions using 6N potassium hydroxide as the electrolytic solution while regulating the negative electrode using sintered nickel hydroxide twice or more times. Charge: 50 mA / g (MH) × 7 h (25 ° C.) Discharge: 50, 300, 600 mA / g (25 ° C.) Final voltage: potential difference between both electrodes = 1 V From FIG. In comparison, it shows that the decrease amount of the discharge capacity is small as the discharge current increases, and the discharge capacity per unit weight or unit volume is large. In Table 2, the unit: mAh / g
It can be seen that the invention example has a larger discharge capacity than the comparative example. Regarding the hydrogen storage characteristics of the hydrogen storage device, the relationship between the hydrogen storage amount and the time was determined by the pressure composition isothermal measurement method by the volumetric method after the activation treatment of hydrogen pressurization. In FIG. 2, 2400 g of a hydrogen storage alloy powder of -40 mesh and 600 g of a binder (Ni powder) were mixed with a V-type powder mixer (comparative example 5 without a binder), and a cylindrical type having a plate fin structure and a volume of about 1 liter was used. After filling in a closed container and performing an activation treatment sufficiently under the following conditions, hydrogen filling characteristics were evaluated. Activation; evacuation × 1 h (60 ° C.) → hydrogen pressurization 10 kg /
FIG. 2 shows the relationship between time and hydrogen storage amount for Invention Example 5 and Comparative Examples 5 and 6 in cm 2 G (0 ° C.). In the invention example, almost 100% of hydrogen was absorbed in about 5 minutes, but in the comparative example, 10% was absorbed.
Or 20 minutes.
【００１９】[0019]
【発明の効果】本発明によればフレーク状の水素吸蔵合
金およびその他金属を使用するので、隙間が小さく接触
面積が大きいので、熱および電気伝導性を向上させるこ
とができ、水素貯蔵装置および水素吸蔵合金電極として
特性が向上し、水素による初期活性化が容易になる。そ
のため、水素の吸蔵高率化および電池としての放電効率
が優れたものが製作可能となる。According to the present invention, since a flake-shaped hydrogen storage alloy and other metals are used, the gaps are small and the contact area is large, so that heat and electric conductivity can be improved. The characteristics of the occlusion alloy electrode are improved, and the initial activation with hydrogen becomes easy. Therefore, it is possible to manufacture a battery having a high hydrogen absorption rate and a high discharge efficiency as a battery.
【図１】本発明の実施例に係る放電電流と放電容量との
関係を示す図である。FIG. 1 is a diagram showing a relationship between a discharge current and a discharge capacity according to an example of the present invention.
【図２】本発明の実施例に係る水素吸蔵量と時間の関係
を示す図である。FIG. 2 is a diagram illustrating a relationship between a hydrogen storage amount and time according to an example of the present invention.
【図３】本発明の水素吸蔵合金のフレーク状と通常の形
状における充填状況を示す図で、（ａ）本発明例、
（ｂ）比較例である。FIGS. 3A and 3B are diagrams showing a filling state of a hydrogen storage alloy of the present invention in a flake shape and a normal shape, and FIG.
(B) Comparative example.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ Ｈ０１Ｍ 4/24 Ｈ０１Ｍ 4/24 Ｊ 4/26 4/26 Ｊ 4/62 4/62 Ｃ ──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 6 Identification code FI H01M 4/24 H01M 4/24 J 4/26 4/26 J 4/62 4/62 C
Claims (8)
あって、フレーク状の水素吸蔵合金粉末と、フレーク状
の他の金属粉末とが均一に混合されてなることを特徴と
する水素貯蔵装置。1. A hydrogen storage device for absorbing and releasing hydrogen, wherein a hydrogen storage alloy powder in a flake form and another metal powder in a flake form are uniformly mixed. apparatus.
伝導性の高い金属からなることを特徴とする請求項１記
載の水素貯蔵装置。2. The hydrogen storage device according to claim 1, wherein the other metal powder is made of a metal having higher thermal conductivity than the hydrogen storage alloy.
性状として、ともに凹凸度合いが４以下であって、かつ
他の金属粉末と水素吸蔵合金粉末の平均直径の比が０．
６以下であることを特徴とする請求項１または２記載の
水素貯蔵装置。3. The surface properties of the hydrogen storage alloy and the other metal powder are each such that the degree of unevenness is 4 or less, and the ratio of the average diameter of the other metal powder to the hydrogen storage alloy powder is 0.1.
The hydrogen storage device according to claim 1, wherein the number is 6 or less.
水素吸蔵合金粉末と、フレーク状の他の金属粉末とが均
一に混合されてなることを特徴とする水素吸蔵合金電
極。4. A hydrogen storage alloy electrode, which is a material of a hydrogen electrode, wherein a flake-shaped hydrogen storage alloy powder and another flake-shaped metal powder are uniformly mixed.
気伝導性の高い金属からなることを特徴とする請求項４
記載の水素吸蔵合金電極。5. The method according to claim 4, wherein the other metal powder is made of a metal having higher electric conductivity than the hydrogen storage alloy.
The hydrogen storage alloy electrode as described in the above.
性状として、ともに凹凸度合いが４以下であって、かつ
他の金属粉末と水素吸蔵合金粉末の平均直径の比が０．
６以下であることを特徴とする請求項４または５記載の
水素吸蔵合金電極。6. The surface properties of the hydrogen storage alloy and the other metal powder are each such that the degree of unevenness is 4 or less, and the ratio of the average diameter between the other metal powder and the hydrogen storage alloy powder is 0.1.
The hydrogen storage alloy electrode according to claim 4 or 5, wherein the number is 6 or less.
製造方法であって、ＢＣＣ相（体心立方）を主相とし、
少量の金属間化合物相が均一に分布したＢＣＣ水素吸蔵
合金を、摩砕効果を付与する粉砕機で擬球形粒子からな
る合金粉末とする工程と、さらに機械的圧力を加えてフ
レーク状とする工程と、該合金粉末とフレーク状の他の
金属粉末とを混合する工程とを有することを特徴とする
請求項１から３のいずれかに記載の水素貯蔵装置の製造
方法。7. A method for producing a hydrogen storage device for absorbing and releasing hydrogen, comprising a BCC phase (body-centered cubic) as a main phase,
A step of converting a BCC hydrogen storage alloy in which a small amount of an intermetallic compound phase is uniformly distributed into an alloy powder composed of pseudo-spherical particles using a pulverizer that imparts a grinding effect, and further forming a flake by applying mechanical pressure. The method for producing a hydrogen storage device according to any one of claims 1 to 3, further comprising: mixing the alloy powder with another metal powder in a flake form.
（体心立方）を主相とし、少量の金属間化合物相が均一
に分布したＢＣＣ水素吸蔵合金を、摩砕効果を付与する
粉砕機で擬球形粒子からなる合金粉末とする工程と、さ
らに機械的圧力を加えてフレーク状とする工程と、該合
金粉末とフレーク状の他の金属粉末とを混合する工程と
を有することを特徴とする請求項４から６のいずれかに
記載の水素吸蔵合金電極の製造方法。8. A method for producing a hydrogen electrode, comprising: grinding a BCC hydrogen storage alloy in which a BCC phase (body-centered cubic) is a main phase and a small amount of an intermetallic compound phase is uniformly distributed to impart a grinding effect. A step of forming an alloy powder composed of pseudo-spherical particles by a machine, a step of further applying mechanical pressure to form a flake, and a step of mixing the alloy powder and another metal powder of the flake. The method for producing a hydrogen storage alloy electrode according to any one of claims 4 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9288529A JPH11116201A (en) | 1997-10-21 | 1997-10-21 | Hydrogen storage device and hydrogen occlusion alloy electrode and their production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9288529A JPH11116201A (en) | 1997-10-21 | 1997-10-21 | Hydrogen storage device and hydrogen occlusion alloy electrode and their production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11116201A true JPH11116201A (en) | 1999-04-27 |
Family
ID=17731429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9288529A Pending JPH11116201A (en) | 1997-10-21 | 1997-10-21 | Hydrogen storage device and hydrogen occlusion alloy electrode and their production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11116201A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3089180A4 (en) * | 2013-12-25 | 2017-08-23 | Ningxia Orient Tantalum Industry Co., Ltd. | Capacitor grade high specific volume tantalum powder improving electrical performance and preparation method therefor |
-
1997
- 1997-10-21 JP JP9288529A patent/JPH11116201A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3089180A4 (en) * | 2013-12-25 | 2017-08-23 | Ningxia Orient Tantalum Industry Co., Ltd. | Capacitor grade high specific volume tantalum powder improving electrical performance and preparation method therefor |
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