JPH04126361A - Manufacture of hydrogen absorbing alloy powder for storage battery and hydrogen absorbing electrode - Google Patents
Manufacture of hydrogen absorbing alloy powder for storage battery and hydrogen absorbing electrodeInfo
- Publication number
- JPH04126361A JPH04126361A JP2249405A JP24940590A JPH04126361A JP H04126361 A JPH04126361 A JP H04126361A JP 2249405 A JP2249405 A JP 2249405A JP 24940590 A JP24940590 A JP 24940590A JP H04126361 A JPH04126361 A JP H04126361A
- Authority
- JP
- Japan
- Prior art keywords
- hydrogen storage
- alloy powder
- hydrogen
- powder
- electrode
- 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.)
- Granted
Links
- 239000001257 hydrogen Substances 0.000 title claims abstract description 166
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 166
- 238000003860 storage Methods 0.000 title claims abstract description 165
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 161
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 138
- 239000000956 alloy Substances 0.000 title claims abstract description 138
- 239000000843 powder Substances 0.000 title claims abstract description 131
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 15
- 238000000034 method Methods 0.000 claims abstract description 41
- 238000009689 gas atomisation Methods 0.000 claims abstract description 21
- 238000010298 pulverizing process Methods 0.000 claims description 11
- 150000002431 hydrogen Chemical class 0.000 abstract description 5
- 238000007599 discharging Methods 0.000 abstract description 3
- 230000000274 adsorptive effect Effects 0.000 abstract 1
- 239000007788 liquid Substances 0.000 abstract 1
- 229910052751 metal Inorganic materials 0.000 description 21
- 239000002184 metal Substances 0.000 description 20
- 239000000203 mixture Substances 0.000 description 19
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 12
- 230000000694 effects Effects 0.000 description 10
- 239000002245 particle Substances 0.000 description 10
- 239000002482 conductive additive Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 230000007423 decrease Effects 0.000 description 8
- 239000007789 gas Substances 0.000 description 8
- 230000014759 maintenance of location Effects 0.000 description 8
- 229910052761 rare earth metal Inorganic materials 0.000 description 8
- 238000012360 testing method Methods 0.000 description 7
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 6
- 229910052759 nickel Inorganic materials 0.000 description 6
- 239000000470 constituent Substances 0.000 description 5
- 239000003792 electrolyte Substances 0.000 description 5
- 150000002910 rare earth metals Chemical class 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 239000003513 alkali Substances 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 4
- 239000006232 furnace black Substances 0.000 description 4
- 239000011148 porous material Substances 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- 238000005984 hydrogenation reaction Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- BFDHFSHZJLFAMC-UHFFFAOYSA-L nickel(ii) hydroxide Chemical compound [OH-].[OH-].[Ni+2] BFDHFSHZJLFAMC-UHFFFAOYSA-L 0.000 description 3
- 238000004080 punching Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910002335 LaNi5 Inorganic materials 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 239000012300 argon atmosphere Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000006258 conductive agent Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 229910000765 intermetallic Inorganic materials 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 235000011837 pasties Nutrition 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920005596 polymer binder Polymers 0.000 description 2
- 239000002491 polymer binding agent Substances 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 230000001603 reducing effect Effects 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 238000005204 segregation Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- 229910018561 MmNi5 Inorganic materials 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- 229910009972 Ti2Ni Inorganic materials 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- IKNAJTLCCWPIQD-UHFFFAOYSA-K cerium(3+);lanthanum(3+);neodymium(3+);oxygen(2-);phosphate Chemical compound [O-2].[La+3].[Ce+3].[Nd+3].[O-]P([O-])([O-])=O IKNAJTLCCWPIQD-UHFFFAOYSA-K 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229920001577 copolymer Polymers 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
- 230000006866 deterioration Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000004816 latex Substances 0.000 description 1
- 229920000126 latex Polymers 0.000 description 1
- 229910001068 laves phase Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000010299 mechanically pulverizing process Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052590 monazite Inorganic materials 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 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
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、アルカリ蓄電池の負極に用いる水素吸蔵合金
粉末の製造方法およびその負極に間するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a hydrogen storage alloy powder used as a negative electrode of an alkaline storage battery, and to the negative electrode.
従来の技術
水素吸蔵電極は、水素の可逆的な吸蔵および放出が可能
な水素吸蔵合金を電極に用いるもので、その水素の電気
化学的な酸化還元反応をアルカリ蓄電池の負極の起電反
応に利用する。水素吸蔵電極に用いられる水素吸蔵合金
には、Ｔ１Ｎｉ、Ｔｉ２Ｎｉ、ＬａＮｉ５およびＴｉＭ
ｎ２などの金属間化合物や、これらの金属間化合物の構
成元素を他の元素で置換したものが用いられている。こ
れらの水素吸蔵合金は、その組成が異なると、水素吸蔵
量、平衡水素圧力、アルカリ電解液中で充放電を繰り返
す場合の保持容量特性などの性質が変化するので、合金
の組成を変えて、水素吸蔵電極の性能の改良が試みられ
ている。Conventional technology Hydrogen storage electrodes use a hydrogen storage alloy that can reversibly store and release hydrogen, and the electrochemical redox reaction of hydrogen is used for the electromotive reaction of the negative electrode of an alkaline storage battery. do. Hydrogen storage alloys used for hydrogen storage electrodes include T1Ni, Ti2Ni, LaNi5 and TiM
Intermetallic compounds such as n2 and compounds in which constituent elements of these intermetallic compounds are replaced with other elements are used. If these hydrogen storage alloys have different compositions, their properties such as hydrogen storage capacity, equilibrium hydrogen pressure, and retention capacity characteristics when repeatedly charged and discharged in an alkaline electrolyte will change, so by changing the composition of the alloy, Attempts have been made to improve the performance of hydrogen storage electrodes.
そして、稀土類系の合金では、ＬａＮｉ５を改良して、
たとえはＭｍＮｉ５，５ｃｏｏ７Ａｌａ ７ （ここで
Ｍｍとは、ミツシュメタルと呼はれる軽稀土類金属の混
合物であり、これに含有される稀土類金属の組成比は、
稀土類元素を多く含有するモナザイトやバストネサイト
などの天然鉱物に含有される稀土類元素の組成比とほぼ
等しい。）、ＭｍＮｉ５．．５Ｃｏｅ４５ＡｌＢ、、Ｍ
ｎ５３のような組成のもの、あるいはこのミツシュメタ
ルの代わりにランタンリッチミツシュメタル（稀土類元
素の内のＣｅ、 Ｎｄ、 Ｓｍなどの有用元素を抽出し
た残存物を還元したり、ミツシュメタルにＬａを添加し
て得たＬａの含有率が高い稀土類金属の混合物。）を用
いるものは、安価で、比較的大きい容量を有し、しかも
充放電サイクル寿命か長いので、実用的な蓄電池用水素
吸蔵合金として用いられている。And for rare earth alloys, we improved LaNi5,
For example, MmNi5,5coo7Ala 7 (here, Mm is a mixture of light rare earth metals called mitshu metal, and the composition ratio of the rare earth metals contained in this is:
The composition ratio of rare earth elements is almost the same as that found in natural minerals such as monazite and bastnaesite, which contain large amounts of rare earth elements. ), MmNi5. ．． 5Coe45AlB,,M
N53-like composition, or instead of this Mitshu metal, use lanthanum-rich Mitshu metal (reducing the residue after extracting useful elements such as Ce, Nd, and Sm among rare earth elements, or adding La to Mitshu metal) A mixture of rare earth metals with a high content of La obtained by It is used as.
また、これらの稀土類系水素吸蔵合金よりもさらに放電
容量が大きい蓄電池用水素吸蔵合金として、Ｌａｖｅｓ
相合金に属し、たとえはＺｒＶｇ、６Ｎｉ、４のような
組成のものや、この合金の成分元素をほかの金属元素で
置換して、電極材料としての性能を改良したものが用い
られようとしている。In addition, Laves is a hydrogen storage alloy for storage batteries that has a larger discharge capacity than these rare earth hydrogen storage alloys.
It belongs to phase alloys, for example, those with compositions such as ZrVg, 6Ni, and 4, and those whose performance as electrode materials are improved by replacing the constituent elements of these alloys with other metal elements are being used. .
これらの水素吸蔵合金は、従来は、アルコン雰囲気下や
真空下で成分元素を溶解し、この溶湯をモールドに流し
込んで鋳込み、この合金塊をショークラッシャーなどて
粒径が１ｍｍ程度になるように機械的に粗粉砕してから
、さらにボールミルなとて機械的に微粉砕したり、ある
いはこの合金に水素の吸蔵放出を行わせ、脆化割れを起
こして微粉砕する方法（水素化粉砕法）で、平均粒径が
たとえは１００μ以下の微粉末を得ていた。Conventionally, these hydrogen-absorbing alloys are produced by melting the component elements in an arcon atmosphere or vacuum, pouring this molten metal into a mold, and then mechanically crushing the alloy mass using a show crusher or other machine to reduce the particle size to about 1 mm. After coarsely pulverizing the alloy, it is further mechanically pulverized using a ball mill, or by causing this alloy to absorb and release hydrogen, causing embrittlement cracking and then pulverizing it into fine particles (hydrogen pulverization method). , a fine powder with an average particle size of, for example, 100 μm or less was obtained.
そして、従来のアルカリ蓄電池用水素吸蔵電極には、こ
れらの方法で製作した水素吸蔵合金粉末を、ポリビニル
アルコール、ポリエチレン、フッ素樹脂、アクリル−ス
チレン樹脂などの耐アルカリ性高分子結着剤で相互に結
合し、パンチングメタルを芯体として水素吸蔵合金を保
持させたものや、発泡ニッケルやニッケル繊維の焼結体
などの耐アルカリ性導電性多孔体の空孔に水素吸蔵合金
の粉末を充填し保持させたものがあった。Conventional hydrogen storage electrodes for alkaline storage batteries are made by bonding the hydrogen storage alloy powder produced by these methods with an alkali-resistant polymer binder such as polyvinyl alcohol, polyethylene, fluororesin, or acrylic-styrene resin. The hydrogen-absorbing alloy powder is then filled into the pores of an alkali-resistant conductive porous material such as a punched metal core that holds the hydrogen-absorbing alloy, or a sintered body of foamed nickel or nickel fiber. There was something.
これらの水素吸蔵電極は、水酸化ニッケル電極などを正
極に用い、水酸化カリウムや水酸化ナトリウムなどのア
ルカリ水溶液を電解液に用いて、構成されるアルカリ蓄
電池の負極に用いられていた。These hydrogen storage electrodes have been used as the negative electrode of alkaline storage batteries, which are constructed using a nickel hydroxide electrode or the like as a positive electrode and an aqueous alkaline solution such as potassium hydroxide or sodium hydroxide as an electrolyte.
発明が解決しようとする課題
従来の蓄電池用水素吸蔵合金粉末を、１回の溶解で数１
０ｋｇ−数トンという大きい規模で製作し、この粉末を
備える負極板と水酸化ニッケル極板などの正極板とを組
み合わせ、アルカリ蓄電池を構成して充放電サイクル試
験を行う場合には、合金の平均組成を同じにして、１回
の溶解でｌＯダラム程度の少量を実験室の規模で製作し
た水素吸蔵合金粉末を備える負極板を用いて構成したア
ルカリ蓄電池の場合よりも、充放電サイクルの進行にと
もなって、負極の放電容量が著しく減少する問題点が発
生した。Problems to be Solved by the Invention Conventional hydrogen-absorbing alloy powder for storage batteries can be melted several times in one go.
When manufacturing on a large scale of 0 kg to several tons, combining a negative electrode plate containing this powder with a positive electrode plate such as a nickel hydroxide electrode plate to form an alkaline storage battery and performing a charge/discharge cycle test, the average of the alloy The charge-discharge cycle progress is much faster than in the case of an alkaline storage battery constructed using a negative electrode plate with the same composition and a negative electrode plate containing a hydrogen-absorbing alloy powder produced on a laboratory scale in a small amount of 1 O duram in one melting. As a result, a problem occurred in that the discharge capacity of the negative electrode was significantly reduced.
課題を解決するための手段
本発明は、ガスアトマイズ法によって製作した水素吸蔵
合金の粉末を粉砕する蓄電池用水素吸蔵合金粉末の製造
方法、およびその方法によって製造した水素吸蔵合金粉
末を備える水素吸蔵電極を提供して、上述の問題点を解
決しようとするものである。Means for Solving the Problems The present invention provides a method for producing hydrogen storage alloy powder for storage batteries, which involves pulverizing hydrogen storage alloy powder produced by a gas atomization method, and a hydrogen storage electrode equipped with the hydrogen storage alloy powder produced by the method. The present invention is intended to solve the above-mentioned problems.
作用
従来の方法で水素吸蔵合金粉末を大きい規模で製作する
場合には、上述のように溶湯をモールドに流し込んで鋳
込むので、溶湯が凝固する際の冷却速度が低くなって、
添加した元素が粒界などに析出する偏析現象が起こり、
合金の組成が不均一になる現象が起こる。このような水
素吸蔵合金粉末を備える負極板をアルカリ電解液に接触
させて充放電を行うと、充放電サイクルの進行にともな
って、負極板の放電容量が著しく減少して、電池の放電
容量か減少する。このような負極板の容量の減少は、水
素吸蔵合金が、たとえはＭｎ、 ＡＩのような１扁析し
ていた添加元素の多い部分から選択的に腐食されて、水
素吸蔵合金粉末の劣化が促進されることに起因するもの
と思われる。Function When producing hydrogen-absorbing alloy powder on a large scale using conventional methods, the molten metal is poured into a mold and cast as described above, so the cooling rate when the molten metal solidifies is slow.
A segregation phenomenon occurs in which added elements precipitate at grain boundaries, etc.
A phenomenon occurs in which the composition of the alloy becomes non-uniform. When a negative electrode plate containing such a hydrogen storage alloy powder is charged and discharged by contacting with an alkaline electrolyte, the discharge capacity of the negative electrode plate decreases significantly as the charge/discharge cycle progresses, and the discharge capacity of the battery decreases. Decrease. This decrease in the capacity of the negative electrode plate is caused by the hydrogen storage alloy being selectively corroded from the parts where there are many added elements, such as Mn and AI, which are precipitated, resulting in deterioration of the hydrogen storage alloy powder. This seems to be due to the fact that it is promoted.
本発明の水素吸蔵合金粉末の製造方法では、まず次のよ
うなガスアトマイズ法によって水素吸蔵合金の粉末を作
る。すなわち、水素吸蔵合金の組成物を、アルゴンガス
やキセノンガスなどの不活性雰囲気中で、高周波誘導炉
などを用いて溶解する。そして、その溶解した合金をこ
れらのガスで加圧して、上述のガス中に噴霧する。この
ようにすると、液滴となって飛散した水嚢吸蔵合金が、
雰囲気のガス中で急速に冷却されて、水素吸蔵合金の粉
末が得られる。In the method for producing hydrogen storage alloy powder of the present invention, first, hydrogen storage alloy powder is produced by the following gas atomization method. That is, a hydrogen storage alloy composition is melted in an inert atmosphere such as argon gas or xenon gas using a high frequency induction furnace or the like. The molten alloy is then pressurized with these gases and sprayed into the above-mentioned gases. In this way, the water sac storage alloy scattered as droplets,
It is rapidly cooled in an atmospheric gas to obtain a powder of hydrogen storage alloy.
この方法では、雰囲気のガスは、希ガスのように、水素
吸蔵合金と容易に反応することがない不活性のものが望
ましい。なぜなら、たとえは、酸素または窒素を含有す
る雰囲気の場合には、高温下ではそれぞれ水素吸蔵合金
の構成金属の酸化物または窒化物が生成して、水素の吸
蔵／放出反応に関与する合金の量が減少するという不都
合が発生するからである。In this method, the atmospheric gas is preferably an inert gas that does not easily react with the hydrogen storage alloy, such as a rare gas. This is because, for example, in the case of an atmosphere containing oxygen or nitrogen, oxides or nitrides of the constituent metals of the hydrogen storage alloy are formed at high temperatures, and the amount of the alloy that participates in the hydrogen storage/release reaction. This is because an inconvenience occurs in that the amount decreases.
このガスアトマイズ法によれは、水素吸蔵合金の凝固が
急激に起こるので、成分元素の偏析がほとんど起こるこ
とがなく、きわめて均一な組成の水素吸蔵合金粉末が得
られる。 ただし、ガスアトマイズ法で得られる水素吸
蔵合金の粉末は、粒径が１００−５００μ程度の粗大な
ものが多く、この粉末をそのまま電極の材料として用い
る場合には、合金の充填密度を高くすることができない
欠点がある。According to this gas atomization method, solidification of the hydrogen storage alloy occurs rapidly, so segregation of component elements hardly occurs, and a hydrogen storage alloy powder having an extremely uniform composition can be obtained. However, the hydrogen storage alloy powder obtained by the gas atomization method is often coarse with a particle size of about 100-500μ, and if this powder is used as an electrode material as it is, it is necessary to increase the packing density of the alloy. There is a drawback that it cannot be done.
また、発明者は、ガスアトマイズ法で製作した水素吸蔵
合金粉末を、そのまま水素吸蔵電極に用いる場合に、次
のような欠点があることも見出した。すなわち、この場
合には、従来のように、溶／
湯をモールドに流し込んで鋳造した合金塊を粉砕して製
作した水素吸蔵合金粉末を用いる場合と比較して、水素
吸蔵合金の重量当たりの放電容量を大きくするために、
大量の導電助剤を必要とする。In addition, the inventors have also discovered that when using the hydrogen storage alloy powder produced by the gas atomization method as it is for a hydrogen storage electrode, there are the following drawbacks. In other words, in this case, compared to the conventional case of using hydrogen storage alloy powder produced by crushing an alloy ingot cast by pouring molten metal into a mold, the discharge per weight of the hydrogen storage alloy is reduced. To increase capacity,
Requires a large amount of conductive aid.
その結果、電極に含まれる水素吸蔵合金粉末の量が少な
くなって、電極の体積当たりの放電容量が小さくなると
いう不都合かある。As a result, the amount of hydrogen-absorbing alloy powder contained in the electrode decreases, resulting in a disadvantage that the discharge capacity per volume of the electrode decreases.
このように、ガスアトマイズ法で製作した水素吸蔵合金
粉末をそのまま水素吸蔵電極に用いる場合に、導電助剤
を大量に必要とする原因は、定かてないが、次のように
推察される。すなわち、ガスアトマイズ法を工業的な規
模で行う際に用いられる不活性カスには、酸素のような
微量の酸化性の成分が不可避的に含まれている。したが
って、溶湯を噴霧すると、その液滴の冷却過程で、高温
の合金表面がこの酸化性の成分によって酸化されて、合
金粉末の表面に導電性か低い酸化物皮膜が生成する。こ
の酸化物皮膜は、常温付近で水素吸蔵合金を粉砕する際
に、この合金粉末の表面に生成する酸化物皮膜と異なっ
て、導電性が低い。そこて、この合金粉末を水素吸蔵電
極に用いる場合には、合金粉末の集電性を良好にして、
その放電容量を大きくするために大量の導電助剤を必要
とする。The reason why a large amount of conductive agent is required when hydrogen storage alloy powder produced by gas atomization is used as it is for a hydrogen storage electrode is not clear, but it is assumed to be as follows. That is, the inert scum used when performing the gas atomization method on an industrial scale inevitably contains trace amounts of oxidizing components such as oxygen. Therefore, when molten metal is sprayed, the high-temperature alloy surface is oxidized by the oxidizing component during the cooling process of the droplets, and an oxide film with low conductivity is formed on the surface of the alloy powder. This oxide film has low conductivity, unlike the oxide film that is formed on the surface of the alloy powder when the hydrogen storage alloy is crushed at around room temperature. Therefore, when using this alloy powder for a hydrogen storage electrode, it is necessary to improve the current collection properties of the alloy powder.
A large amount of conductive additive is required to increase the discharge capacity.
そこで、本発明では、このような問題点を解決するため
に、ガスアトマイズ法で製作した水素吸蔵合金粉末を、
さらに、ボールミルなどで機械的に微粉砕したり、ある
いは水素の吸蔵放出を行わせて微粉砕して、平均粒径が
たとえは１００μ以下の微細な水素吸蔵合金を製作する
。そして、本発明の水素吸蔵電極は、この方法で製作し
た水素吸蔵合金粉末を、ポリビニルアルコール、ポリエ
チレン、フッ素樹脂、アクリル−スチレン樹脂なとの耐
アルカリ性高分子結着剤で相互に結合し、パンチングメ
タルを芯体として水素吸蔵合金を保持させたものや、発
泡ニッケルやニッケル繊維の焼結体などの耐アルカリ性
導電性多孔体の空孔に水素吸蔵合金の粉末を充填し保持
させたものである。Therefore, in the present invention, in order to solve such problems, hydrogen storage alloy powder produced by the gas atomization method is
Further, a fine hydrogen storage alloy having an average particle size of, for example, 100 μm or less is produced by mechanically pulverizing it with a ball mill or the like, or by pulverizing it by absorbing and desorbing hydrogen. The hydrogen storage electrode of the present invention is produced by bonding the hydrogen storage alloy powder produced by this method with an alkali-resistant polymer binder such as polyvinyl alcohol, polyethylene, fluororesin, or acrylic-styrene resin, and punching it. These include metal cores that hold hydrogen storage alloys, and hydrogen storage alloy powder that is held by filling the pores of alkali-resistant conductive porous materials such as foamed nickel or sintered nickel fibers. .
本発明の方法で製作した水素吸蔵合金粉末は、上述のよ
うに急速に冷却されているので、成分元素はほとんど偏
析していない。したがってこの水素吸蔵合金粉末を備え
る本発明の水素吸蔵電極は、その水素吸蔵合金粉末がア
ルカリ電解液中で腐食される速度が小さいので、この電
極を用いるアルカリ蓄電池の充放電サイクルをおこなっ
た場合に、放電容量が急激に減少するという不都合が解
決される。Since the hydrogen storage alloy powder produced by the method of the present invention is rapidly cooled as described above, the component elements are hardly segregated. Therefore, the hydrogen storage electrode of the present invention including this hydrogen storage alloy powder has a low corrosion rate in an alkaline electrolyte, so when an alkaline storage battery using this electrode is charged and discharged, This solves the problem of a sudden decrease in discharge capacity.
さらに、本発明の方法で製作した水素吸蔵合金粉末を備
える本発明の水素吸蔵電極は、ガスアトマイズ法で製作
した水素吸蔵合金粉末を、本発明の水素吸蔵合金粉末と
同じ粒度範囲で、粉砕することなくそのまま備える水素
吸蔵電極と比較して、導電助剤の量が少なくても、大き
い放電容量が得られる。この現象の真の原因は、まだ明
かてないが、次のように考えられる。すなわち、ガスア
トマイズ法で製作した水素吸蔵合金粉末の表面の多くは
、高温下で生成した導電性が低い酸化物皮膜で覆われて
いる。しかし、この粉末を粉砕すると、合金の破断によ
って新たな表面が生成し、この新主面に生成する酸化物
皮膜は、高温下で生成する酸化物皮膜と異なって、導電
性が比較的高いので、この水素吸蔵合金粉末を備える水
素吸蔵電極は、少量の導電助剤を用いるだけで、あるい
は、合金の種類によっては、導電助剤を用いなくとも、
大きい放電容量が得られる。Further, the hydrogen storage electrode of the present invention comprising the hydrogen storage alloy powder produced by the method of the present invention can be obtained by pulverizing the hydrogen storage alloy powder produced by the gas atomization method to the same particle size range as the hydrogen storage alloy powder of the present invention. Compared to a hydrogen storage electrode that is provided without any modification, a large discharge capacity can be obtained even with a small amount of conductive additive. The true cause of this phenomenon is not yet clear, but it is thought to be as follows. That is, most of the surface of the hydrogen storage alloy powder produced by the gas atomization method is covered with an oxide film with low conductivity that is generated at high temperatures. However, when this powder is pulverized, a new surface is generated due to the fracture of the alloy, and the oxide film that forms on this new main surface has relatively high conductivity, unlike the oxide film that forms at high temperatures. A hydrogen storage electrode comprising this hydrogen storage alloy powder can be produced by using only a small amount of conductive additive or, depending on the type of alloy, without using a conductive additive.
Large discharge capacity can be obtained.
なお、この作用をいっそう確実にするためには、ガスア
トマイズ法で製作した水素吸蔵合金粉末を予めふるい分
けて、たとえば粒径が４５μ以下のような微粉末を除去
してから粉砕すると、表面が高温下で生成した酸化物皮
膜で覆われた不活性な合金粉末の含有率が小さくなるの
で好適である。In order to make this effect even more reliable, it is recommended that the hydrogen storage alloy powder produced by the gas atomization method be sieved in advance to remove fine powder with a particle size of 45 μm or less before being crushed. This is preferable because the content of the inert alloy powder covered with the oxide film produced in step 1 is reduced.
このように、本発明の方法で製作した水素吸蔵合金粉末
を備える本発明の水素吸蔵電極は、充放電サイクルの進
行にともなう容量減少を抑制する作用と、導電助剤が少
量の場合にも大きい放電容量が得られる作用とを兼ね備
えている。As described above, the hydrogen storage electrode of the present invention, which includes the hydrogen storage alloy powder produced by the method of the present invention, has the effect of suppressing capacity reduction as the charge/discharge cycle progresses, and has a large effect even when a small amount of conductive additive is used. It also has the function of providing discharge capacity.
また、本発明の水素吸蔵合金粉末の製造方法によれば、
従来の方法のように、溶湯をモールドで凝固させてから
粉砕して粗粉末を得る代わりに、粗粉末か溶湯から直接
溝られるので、工程が簡単になって、水素吸蔵合金粉末
の製造コストを低減する作用もある。Further, according to the method for producing hydrogen storage alloy powder of the present invention,
Instead of solidifying the molten metal in a mold and then pulverizing it to obtain coarse powder as in the conventional method, the coarse powder or molten metal is directly grooved, which simplifies the process and reduces the manufacturing cost of hydrogen-absorbing alloy powder. It also has a reducing effect.
実施例
以下の実施例によって、本発明をさらに詳しく説明する
。EXAMPLES The present invention will be explained in more detail with the following examples.
［水素吸蔵合金粉末Ａ］ （本発明実施例）合計で１
００ｋｇのミツシュメタル（原料はバストネサイト）、
ニッケル、コバルト、アルミニウムおよびマンガンを、
化学式ＭｍＮｉ５，６５Ｃｏ、７５Ａｌ、４Ｍｎ［１，
３になるように、アルゴン雰囲気にした高周波誘導炉中
で溶解し、この溶湯をアルゴン雰囲気中へアルゴンカス
で噴霧するガスアトマイズ法によって、水素吸蔵合金の
粗粉末を製作した。次に、この粗粉末を、分級すること
なく、そのままエタノールで湿潤させて、アルミナ製の
ポットおよびボールを用いてボールミル粉砕をおこなっ
た。そして、この粉末を真空乾燥してから分級し、３３
０メツシユの篩いを通過した水素吸蔵合金の微粉末Ａを
得た。[Hydrogen storage alloy powder A] (Example of the present invention) 1 in total
00kg of Mitshumetal (raw material is bastnesite),
nickel, cobalt, aluminum and manganese,
Chemical formula MmNi5,65Co, 75Al, 4Mn[1,
3, a crude powder of a hydrogen storage alloy was produced by a gas atomization method in which the molten metal was melted in a high frequency induction furnace in an argon atmosphere and sprayed with an argon gas into the argon atmosphere. Next, this coarse powder was moistened with ethanol as it was without being classified, and ball-milled using an alumina pot and balls. Then, this powder is vacuum dried and then classified.
A fine powder A of hydrogen storage alloy which passed through a 0 mesh sieve was obtained.
［水素吸蔵合金粉末Ｂｌ （本発明実施例）粗粉末の
段階までの合金組成および粗粉末の製造方法は、水素吸
蔵合金粉末Ａの場合と同しにして、この粗粉末を、２０
ｋｇ／ｃｍの圧力の水素雰囲気のもとて１００℃に昇温
しで水素化し、ついて、常温下で油回転真空１ポンプで
減圧にして脱水素化し、この水素の吸蔵・放出にともな
う脆化割れによって、水素吸蔵合金を微粉化させた。そ
して、この微粉末を３３０メツシユの篩いて分級して、
篩いを通過した水素吸蔵合金の微粉末Ｂを得た。[Hydrogen storage alloy powder Bl (Embodiment of the present invention) The alloy composition up to the coarse powder stage and the manufacturing method of the coarse powder are the same as in the case of hydrogen storage alloy powder A.
Under a hydrogen atmosphere with a pressure of kg/cm, the temperature is raised to 100°C to hydrogenate, and then at room temperature, the pressure is reduced using an oil rotary vacuum pump to dehydrogenate, resulting in embrittlement due to the absorption and release of hydrogen. The cracking caused the hydrogen storage alloy to become pulverized. Then, this fine powder is sieved through a 330-mesh sieve and classified.
Fine powder B of hydrogen storage alloy that passed through the sieve was obtained.
［水素吸蔵合金粉末Ｃ］ （本発明実施例）粗粉末の
段階までの合金組成および粗粉末の製造方法は、水素吸
蔵合金粉末Ａの場合と同じにして、この粗粉末を、粉砕
することなくそのまま分級し、３３０メツシユの篩いを
通過する微粉末を除去してから、水素吸蔵合金粉末Ａの
場合と同様のエタノールで湿潤させるボールミル粉砕を
行い、真空乾燥してから再度分級し、３３０メツシユの
篩いを通過した水素吸蔵合金の微粉末Ｃを得た。[Hydrogen storage alloy powder C] (Embodiment of the present invention) The alloy composition up to the coarse powder stage and the method for producing the coarse powder are the same as in the case of hydrogen storage alloy powder A, and this coarse powder is processed without pulverization. After classifying as it is and removing the fine powder that passes through a 330 mesh sieve, it is crushed in a ball mill where it is moistened with ethanol in the same way as in the case of hydrogen storage alloy powder A, vacuum dried, and then classified again to obtain a 330 mesh sieve. A fine powder C of hydrogen storage alloy that passed through the sieve was obtained.
［水素吸蔵合金粉末Ｄ］ （従来例）水素吸蔵合金粉
末Ａの場合と同し組成の溶湯１００ｋｇを、直径１０ｃ
ｍの鉄製のモールドに流し込んで鋳込み、この鋳造物を
ショークラッシャーて粗粉砕し、ふるい分けて、粒径が
１ｍｍ以下の粗粉末を得た。次に、この粗粉末を、水素
吸蔵合金粉末Ａの場合と同じ条件でホールミルで粉砕し
、３３０メツシユの篩いを通過した水素吸蔵合金の微粉
末りを得た。[Hydrogen storage alloy powder D] (Conventional example) 100 kg of molten metal having the same composition as hydrogen storage alloy powder A was heated to a diameter of 10 cm.
The cast material was poured into an iron mold of 1 mm in size and cast, and the cast product was coarsely crushed using a show crusher and sieved to obtain a coarse powder with a particle size of 1 mm or less. Next, this coarse powder was pulverized in a whole mill under the same conditions as in the case of hydrogen storage alloy powder A to obtain a fine powder of hydrogen storage alloy that passed through a 330 mesh sieve.
［水素吸蔵合金粉末Ｅ］ （比較例）粗粉末の段階ま
での合金組成および粗粉末の製造方法は、水素吸蔵合金
粉末Ａの場合と同じにして、この粗粉末を、粉砕するこ
となくそのまま篩い分けて、３３０メツシユの篩いを通
過した水素吸蔵合金の微粉末Ｅを得た。[Hydrogen storage alloy powder E] (Comparative example) The alloy composition up to the coarse powder stage and the manufacturing method of the coarse powder were the same as in the case of hydrogen storage alloy powder A, and this coarse powder was sieved as it was without pulverizing. The mixture was separated to obtain fine powder E of a hydrogen storage alloy that passed through a 330 mesh sieve.
次に、本発明の水素吸蔵電極（ア）は、次のようにして
製作した。すなわち、本発明の製造方法で製作した水素
吸蔵合金粉末Ａ１００重量部、導電助剤たるファーネス
ブラック２重量部およびアクリル−スチレン共重合体か
らなる合成ラテックス２重量部（固形分）に水を加えて
ペースト状混合物を調製し、このペースト状混合物を、
厚さがＯ，１ｍｍで開口率が約０．５のニッケルメッキ
した鉄製パンチングメタルの両面に塗布し、乾燥してか
ら、１００℃に加熱したロールの間を通過させてプレス
し、所定の寸法に打ち抜いて水素吸蔵電極（ア）を製作
した。Next, the hydrogen storage electrode (A) of the present invention was manufactured as follows. That is, water was added to 100 parts by weight of hydrogen storage alloy powder A produced by the production method of the present invention, 2 parts by weight of furnace black as a conductive agent, and 2 parts by weight (solid content) of a synthetic latex made of an acrylic-styrene copolymer. A pasty mixture is prepared, and this pasty mixture is
It is applied to both sides of nickel-plated iron punching metal with a thickness of 0.1 mm and an aperture ratio of approximately 0.5, dried, and then passed between rolls heated to 100°C and pressed to the specified dimensions. A hydrogen storage electrode (A) was produced by punching out the material.
本発明の水素吸蔵電極（イ）は、水素吸蔵電極（アー）
における水素吸蔵合金粉末への代わりに水素吸蔵合金粉
末Ｂを用いて、そのほかは電極（ア）と同じに構成した
。The hydrogen storage electrode (A) of the present invention is a hydrogen storage electrode (A).
Hydrogen storage alloy powder B was used instead of the hydrogen storage alloy powder in , and the other configuration was the same as electrode (A).
本発明の水素吸蔵電極（つ）は、水素吸蔵電極（ア）に
おける水素吸蔵合金粉末Ａの代わりに水素吸蔵合金粉末
Ｃを用いて、そのほかは電極（アＰと同じに構成した。The hydrogen storage electrode (2) of the present invention was constructed in the same manner as the electrode (A) except that hydrogen storage alloy powder C was used in place of the hydrogen storage alloy powder A in the hydrogen storage electrode (A).
従来の水素吸蔵電極（１）は、水素吸蔵電極（ア）にお
ける水素吸蔵合金粉末への代わりに水素吸蔵合金粉末り
を用いて、そのほかは電極（ア）と同じに構成した。The conventional hydrogen storage electrode (1) was constructed in the same manner as the electrode (A) except that hydrogen storage alloy powder was used instead of the hydrogen storage alloy powder in the hydrogen storage electrode (A).
比較例の水素吸蔵電極（オ）は、水素吸蔵電極（ア）に
おける水素吸蔵合金粉末Ａの代わりに水素吸蔵合金粉末
Ｅを用いて、そのほかは電極（ア）と同じに構成した。The hydrogen storage electrode (E) of the comparative example was constructed in the same manner as the electrode (A) except that hydrogen storage alloy powder E was used in place of the hydrogen storage alloy powder A in the hydrogen storage electrode (A).
比較例の水素吸蔵電極（力）は、水素吸蔵電極（オ）に
おけるファーネスブラック２重量部の代わりに、同じフ
ァーネスブラック６重量部を用いて、そのほかは電極（
オ）と同じに構成した。The comparative hydrogen storage electrode (force) used 6 parts by weight of the same furnace black instead of the 2 parts by weight of the furnace black in the hydrogen storage electrode (O), and the rest of the electrode (
It was configured the same as (e).
以上の６つの水素吸蔵電極の放電容量および充放電サイ
クル寿命特性を調べるために次の試験を行った。すなわ
ち、どの水素吸′ｉ！！２電極も、１枚に６グラムの水
素吸蔵合金粉末を含むように切断して、その１枚を負極
とした。そして、電池の放電容量が負極の放電容量を表
すようにするために、正極には、負極よりも放電容量が
大きくなるように、１枚の放電容量が１５００ｍＡ１１
の焼結式水酸化ニッケル電極を２枚用い、これらを、負
極の両側に極間距離が２．５ｃｍになるように配置した
。そして、５．８Ｍの濃度の水酸化カリウム電解液を用
いて、フラッデツドタイプの開放型の試験用電池を構成
した。負極に上記の水素吸蔵電極（ア）、（イ）、（つ
）、（オ）および（力）を用いた試験用アルカリ蓄電池
を、それぞれ（あ）、くい）、（う）、くえ）、（お）
および（か）と呼ぶ。The following tests were conducted to investigate the discharge capacity and charge/discharge cycle life characteristics of the above six hydrogen storage electrodes. That is, which hydrogen absorption'i! ! Two electrodes were also cut so that each sheet contained 6 grams of hydrogen storage alloy powder, and one of the sheets was used as a negative electrode. In order to make the discharge capacity of the battery represent the discharge capacity of the negative electrode, the positive electrode has a discharge capacity of 1500 mA11 so that the discharge capacity is larger than that of the negative electrode.
Two sintered nickel hydroxide electrodes were used, and these were placed on both sides of the negative electrode so that the distance between the electrodes was 2.5 cm. A flooded open test battery was constructed using a potassium hydroxide electrolyte having a concentration of 5.8M. Test alkaline storage batteries using the above hydrogen storage electrodes (A), (B), (T), (O) and (R) as negative electrodes were respectively (A), KU), (U), KU), (oh)
and (ka).
つぎに、これらの試験用電池を、２５℃において、８０
０ｍＡの電流で２．４時間充電し、８００ｍＡの電流で
端子電圧帆８ｖまで放電する条件で、充放電サイクル試
験をおこなった。この試験におけるＩＯサイクル目の放
電容量および３００サイクル目の容量保持率（３００サ
イクル目と１０サイクル目との放電容量の比）を、第１
表に示す。Next, these test batteries were heated to 80°C at 25°C.
A charge/discharge cycle test was conducted under the conditions of charging with a current of 0 mA for 2.4 hours and discharging with a current of 800 mA to a terminal voltage of 8 V. In this test, the discharge capacity at the IO cycle and the capacity retention rate at the 300th cycle (the ratio of the discharge capacity at the 300th cycle and the 10th cycle) were
Shown in the table.
（以下余白）
第１表
第１表から、１０サイクル目の放電容量に関して、次の
ことがわかる。(The following is a blank space) Table 1 From Table 1, the following can be seen regarding the discharge capacity at the 10th cycle.
すなわち、本発明の方法で製造した水素吸蔵合金粉末Ａ
およびＢを備える水素吸蔵電極を用いる電池（あ）およ
び（い）の放電容量は、従来の方法で製造した水素吸蔵
合金粉末りを備える水素吸蔵電極を用いる電池（え）の
放電容量にほぼ等しい。That is, hydrogen storage alloy powder A produced by the method of the present invention
The discharge capacities of batteries (A) and (B) using hydrogen storage electrodes comprising and B are approximately equal to the discharge capacity of battery (E) using hydrogen storage electrodes comprising hydrogen storage alloy powder manufactured by a conventional method. .
そして、ガスアトマイズ法で得られた粉末の内で、微粉
末を除去してから粉砕する本発明の方法で製造した水素
吸蔵合金粉末Ｃを備える水素吸蔵電極を用いる電池（う
）の放電容量は、微粉末を除去することなく粉砕する本
発明の方法で製造した水素吸蔵合金粉末ＡおよびＢを備
える水素吸蔵電極を用いる電池（あ）および（い）の放
電容量よりも著しく大きい。Then, the discharge capacity of a battery (c) using a hydrogen storage electrode comprising hydrogen storage alloy powder C manufactured by the method of the present invention in which fine powder is removed from the powder obtained by the gas atomization method and then pulverized is as follows. This is significantly larger than the discharge capacity of batteries (A) and (B) using hydrogen storage electrodes comprising hydrogen storage alloy powders A and B produced by the method of the present invention in which fine powder is pulverized without removing it.
そして、ガスアトマイズ法で得られた粉末の内で、粉砕
しない微粉末をそのまま用いる比較例の方法で製造した
水素吸蔵合金粉末Ｅを備えて、本発明の水素吸蔵電極と
同じ少量の導電助剤を添加した水素吸蔵電極を用いる電
池（お）の放電容量は、粉砕して微粉末を得る本発明の
方法で製造した水素吸蔵合金粉末ＡおよびＢを備える水
素吸蔵電極を用いる電池（あ）および（い）の放電容量
よりも、著しく小さい。Then, among the powders obtained by the gas atomization method, a hydrogen storage alloy powder E manufactured by the method of the comparative example using the fine powder that is not crushed as it is was provided, and a small amount of the conductive aid same as that of the hydrogen storage electrode of the present invention was added. The discharge capacity of the battery (O) using the added hydrogen storage electrode is the same as that of the battery (A) using the hydrogen storage electrode equipped with the hydrogen storage alloy powder A and B produced by the method of the present invention which is pulverized to obtain a fine powder. This is significantly smaller than the discharge capacity of
また、ガスアトマイズ法で得られた粉末の内で、粉砕し
ない微粉末をそのまま用いる比較例の方法で製造した水
素吸蔵合金粉末Ｅを備えて、本発明の水素吸蔵電極の場
合の３倍の量の導電助剤を添加する比較例の水素吸蔵電
極を用いる電池（か）では、放電容量か電池（お）より
も大きくなっている。しかしながら、電池（か）の放電
容量は、粉砕して微粉末を得る本発明の方法で製造した
水素吸蔵合金粉末を備えて、しかも、少量の導電助剤を
添加する本発明の水素吸蔵電極を用いる電池（あ）およ
び（い）の放電容量よりも、まだ小さい値に過ぎない。In addition, among the powders obtained by the gas atomization method, hydrogen storage alloy powder E manufactured by the method of the comparative example using fine powder without pulverization was used, and the amount of hydrogen storage electrode was three times that of the hydrogen storage electrode of the present invention. The discharge capacity of the battery (2) using the hydrogen storage electrode of the comparative example in which a conductive additive is added is larger than that of the battery (2). However, the discharge capacity of the battery is limited by the hydrogen storage electrode of the present invention, which is equipped with the hydrogen storage alloy powder produced by the method of the present invention which is crushed to obtain a fine powder, and in which a small amount of conductive additive is added. This value is still only smaller than the discharge capacity of the batteries (A) and (B) used.
さらに、導電助剤のファーネスブラックは嵩高いのて、
これを大量に用いる比較例の水素吸蔵電極（力）の体積
は、本発明の水素吸蔵電極（ア）、（イ）および（つ）
よりも２０％も大きくなってしまった。ちなみに、水素
吸蔵電極（ア）、（イ）、（つ）、（１）および（オ）
の体積はは等しかった。Furthermore, since the conductive additive furnace black is bulky,
The volume of the hydrogen storage electrode (force) of the comparative example using a large amount of this is the hydrogen storage electrode (A), (B) and (T) of the present invention.
It has grown by 20%. By the way, hydrogen storage electrodes (a), (b), (tsu), (1) and (e)
The volumes of were equal.
つぎに、第１表から、３００サイクル目の容量保持率に
間して次のことがわかる。Next, from Table 1, the following can be seen regarding the capacity retention rate at the 300th cycle.
すなわち、本発明および比較例のガスアトマイズ法で製
造した水素吸蔵合金粉末を備える水素吸蔵電極を用いる
電池（あ）、（い）、（う）、（お）および（か）の容
量保持率は、９０％以上の高い値である。一方、従来の
鋳造法で製造した水素吸蔵合金粉末を備える水素吸蔵電
極を用いる゛電池（え）の容量保持率は、著しく小さい
。That is, the capacity retention rates of batteries (A), (I), (U), (O), and (K) using hydrogen storage electrodes comprising hydrogen storage alloy powders manufactured by the gas atomization method of the present invention and comparative examples are as follows: This is a high value of over 90%. On the other hand, the capacity retention rate of a battery using a hydrogen storage electrode comprising a hydrogen storage alloy powder manufactured by a conventional casting method is extremely low.
なお、本実施例では、水素吸蔵合金として、ＭｍＮ＋１
５５Ｃ０１１，７５ＡＩｌ！、４Ｍｎ［１，３の組成の
ものを用いた場合を説明したが、Ｍｍとその他の成分元
素の合計との比を一定にしたまま、その構成元素の比を
変化させた場合、ミツシュメタルの代わりにランタンリ
ッチミツシュメタルを用いる場合、Ｎ１の一部をＭｎテ
置換しない場合、あるいはＺｒＶｌ！、６Ｎｉｌｌ、、
やその成分元素を変化させたＬａｖｅｓ相合金を用いる
場合にも、同様の効果が認められた。In this example, MmN+1 is used as the hydrogen storage alloy.
55C011,75AIl! , 4Mn[1,3] However, if the ratio of the constituent elements is changed while keeping the ratio of Mm to the sum of other constituent elements constant, it is possible to replace Mitsushmetal. When using lanthanum-rich Mitsushmetal, when part of N1 is not replaced with Mnte, or when using ZrVl! ,6Nill,,
Similar effects were also observed when using Laves phase alloys with different component elements.
また、水素吸蔵合金として、ＣｅＣＩ型の結晶構造を有
するＴ１Ｎｉ合金を用いる場合には、そもそも、この合
金の機械的粉砕が困難であるので、溶湯をガスアトマイ
ズ法で粉末にしてから、さらに水素化粉砕する本発明の
方法で微粉砕した粉末を備える水素吸蔵電極と、溶湯を
モールドで凝固させてから、水素化粉砕を繰り返す従来
の方法で微粉砕した粉末を備える水素吸蔵電極とを比較
した結果、本発明の方法で製造したＴ１Ｎｉ合金の微粉
末を備える本発明の電極は、充放電サイクルの進行にと
もなう容量保持特性が良好であ）た。さらに、この合金
の場合にも、ガスアトマイズ法で製造した粉末を、水素
化粉砕することなく分級して得た微粉末と、水素化粉砕
して得た微粉末とを比較すると、後者を備える水素吸蔵
電極の放電容量が大きかった。In addition, when using a T1Ni alloy with a CeCI type crystal structure as a hydrogen storage alloy, it is difficult to mechanically crush this alloy in the first place, so the molten metal is made into powder using a gas atomization method, and then further hydrogenated and crushed. As a result of comparing a hydrogen storage electrode comprising a powder finely pulverized by the method of the present invention and a hydrogen storage electrode comprising a powder pulverized by a conventional method of solidifying a molten metal in a mold and then repeating hydrogenation grinding, The electrode of the present invention comprising the T1Ni alloy fine powder produced by the method of the present invention had good capacity retention characteristics as charge/discharge cycles progressed. Furthermore, in the case of this alloy as well, when comparing the fine powder obtained by classifying the powder produced by the gas atomization method without hydrogenation grinding and the fine powder obtained by hydrogenation grinding, it is found that the latter contains hydrogen. The discharge capacity of the storage electrode was large.
したがって、本発明の水素吸蔵合金粉末の製造方法およ
び水素吸蔵電極は、水素吸蔵合金の種類に関わらず有効
であるといえる。Therefore, it can be said that the method for producing hydrogen storage alloy powder and the hydrogen storage electrode of the present invention are effective regardless of the type of hydrogen storage alloy.
また、本実施例では、水素吸蔵電極として、水素吸蔵合
金粉末をパンチングメタルに保持させたものを説明した
が、発泡ニッケルなどの３次元多孔体に水素吸蔵合金粉
末を保持させる電極の場合にも、全く同様の効果が得ら
れる。In addition, in this example, an electrode in which hydrogen-absorbing alloy powder is held in a punched metal was explained as a hydrogen-absorbing electrode, but an electrode in which hydrogen-absorbing alloy powder is held in a three-dimensional porous body such as foamed nickel may also be used. , exactly the same effect can be obtained.
さらに、上記の実施例では、３３０メツシユの篩い（篩
いの目の開き４５μ）を通過した水素吸蔵合金粉末を備
える水素吸蔵電極について説明したが、本発明の効果を
発揮する合金粉末の粒径の範囲は、この粒度に限定され
るものではない。実用的な見地からは、水素吸蔵合金粉
末をペースト状にして、その沈降速度を小さくしたり、
３次元多孔体に水素吸蔵合金粉末を充填するためには、
粒径か小さい粉末が望ましく、１００メツシユの篩い（
篩いの目の開き１５０μ）を通過した程度のものまでで
あれは好適である。Furthermore, in the above example, a hydrogen storage electrode was described that includes a hydrogen storage alloy powder that has passed through a 330 mesh sieve (sieve opening 45μ), but the particle size of the alloy powder that exhibits the effects of the present invention is The range is not limited to this particle size. From a practical point of view, it is possible to reduce the sedimentation rate by turning hydrogen-absorbing alloy powder into a paste,
In order to fill a three-dimensional porous body with hydrogen-absorbing alloy powder,
Powder with a small particle size is preferable, and sieved with 100 mesh (
It is suitable that the material passes through a sieve with an opening of 150 μm.
発明の効果
本発明の水素吸蔵合金粉末の製造方法および水素吸蔵電
極は、充放電サイクルの進行にともなうアルカリ蓄電池
用水素吸蔵電極の容量保持特性が良好になるという効果
と、導電助剤が少量でもアルカリ蓄電池用水素吸蔵電極
の放電容量が大きくなるという効果とを兼ね備えている
。Effects of the Invention The method for producing a hydrogen storage alloy powder and the hydrogen storage electrode of the present invention have the effect that the capacity retention characteristics of the hydrogen storage electrode for an alkaline storage battery as the charge/discharge cycle progresses are improved, and the hydrogen storage electrode has the effect that the capacity retention characteristics of the hydrogen storage electrode for an alkaline storage battery are improved even with a small amount of conductive additive. This also has the effect of increasing the discharge capacity of the hydrogen storage electrode for alkaline storage batteries.
Claims (2)
の粉末を粉砕することを特徴とする蓄電池用水素吸蔵合
金粉末の製造方法。(1) A method for producing hydrogen storage alloy powder for storage batteries, which comprises pulverizing hydrogen storage alloy powder produced by a gas atomization method.
蔵合金粉末を備えることを特徴とする水素吸蔵電極。(2) A hydrogen storage electrode comprising a hydrogen storage alloy powder produced by the method according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2249405A JP2972919B2 (en) | 1990-09-18 | 1990-09-18 | Method for producing hydrogen storage alloy powder for storage battery and hydrogen storage electrode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2249405A JP2972919B2 (en) | 1990-09-18 | 1990-09-18 | Method for producing hydrogen storage alloy powder for storage battery and hydrogen storage electrode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04126361A true JPH04126361A (en) | 1992-04-27 |
| JP2972919B2 JP2972919B2 (en) | 1999-11-08 |
Family
ID=17192494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2249405A Expired - Fee Related JP2972919B2 (en) | 1990-09-18 | 1990-09-18 | Method for producing hydrogen storage alloy powder for storage battery and hydrogen storage electrode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2972919B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5376474A (en) * | 1993-02-05 | 1994-12-27 | Sanyo Electric Co., Ltd. | Hydrogen-absorbing alloy for a negative electrode and manufacturing method therefor |
| US5605585A (en) * | 1993-07-15 | 1997-02-25 | Matsushita Electric Industrial Co., Ltd. | Method for producing hydrogen storage alloy particles and sealed-type nickel-metal hydride storage battery using the same |
| US5616435A (en) * | 1994-07-22 | 1997-04-01 | Sanyo Electric Co., Ltd. | Hydrogen-absorbing alloy electrode for metal hydride alkaline battery |
| DE10163713A1 (en) * | 2001-12-21 | 2003-07-10 | Geesthacht Gkss Forschung | Production of metal powders using a gas atomization comprises charging the metal with hydrogen after pulverization |
-
1990
- 1990-09-18 JP JP2249405A patent/JP2972919B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5376474A (en) * | 1993-02-05 | 1994-12-27 | Sanyo Electric Co., Ltd. | Hydrogen-absorbing alloy for a negative electrode and manufacturing method therefor |
| US5605585A (en) * | 1993-07-15 | 1997-02-25 | Matsushita Electric Industrial Co., Ltd. | Method for producing hydrogen storage alloy particles and sealed-type nickel-metal hydride storage battery using the same |
| US5616435A (en) * | 1994-07-22 | 1997-04-01 | Sanyo Electric Co., Ltd. | Hydrogen-absorbing alloy electrode for metal hydride alkaline battery |
| DE10163713A1 (en) * | 2001-12-21 | 2003-07-10 | Geesthacht Gkss Forschung | Production of metal powders using a gas atomization comprises charging the metal with hydrogen after pulverization |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2972919B2 (en) | 1999-11-08 |
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