JPH0762475A - Rare earth element-containing hydrogen occluding alloy for alkali storage battery - Google Patents
Rare earth element-containing hydrogen occluding alloy for alkali storage batteryInfo
- Publication number
- JPH0762475A JPH0762475A JP5235558A JP23555893A JPH0762475A JP H0762475 A JPH0762475 A JP H0762475A JP 5235558 A JP5235558 A JP 5235558A JP 23555893 A JP23555893 A JP 23555893A JP H0762475 A JPH0762475 A JP H0762475A
- Authority
- JP
- Japan
- Prior art keywords
- rare earth
- neodymium
- cobalt
- alloy
- hydrogen storage
- 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
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 56
- 239000000956 alloy Substances 0.000 title claims abstract description 56
- 238000003860 storage Methods 0.000 title claims abstract description 47
- 239000001257 hydrogen Substances 0.000 title claims abstract description 38
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 38
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 37
- 229910052761 rare earth metal Inorganic materials 0.000 title claims abstract description 26
- 239000003513 alkali Substances 0.000 title abstract 3
- 229910052779 Neodymium Inorganic materials 0.000 claims abstract description 38
- 150000002910 rare earth metals Chemical class 0.000 claims abstract description 21
- 229910052746 lanthanum Inorganic materials 0.000 claims abstract description 9
- 239000000203 mixture Substances 0.000 claims abstract description 5
- 229910017052 cobalt Inorganic materials 0.000 claims description 33
- 239000010941 cobalt Substances 0.000 claims description 33
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 33
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 claims description 33
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 25
- 229910052759 nickel Inorganic materials 0.000 claims description 12
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims description 8
- 239000011572 manganese Substances 0.000 claims description 5
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 3
- 238000005260 corrosion Methods 0.000 abstract description 12
- 230000007797 corrosion Effects 0.000 abstract description 12
- 230000000704 physical effect Effects 0.000 abstract description 5
- 238000005275 alloying Methods 0.000 abstract description 4
- 230000001105 regulatory effect Effects 0.000 abstract description 3
- 230000003647 oxidation Effects 0.000 description 7
- 238000007254 oxidation reaction Methods 0.000 description 7
- 230000007423 decrease Effects 0.000 description 6
- 238000007599 discharging Methods 0.000 description 5
- 229910052684 Cerium Inorganic materials 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 229910001122 Mischmetal Inorganic materials 0.000 description 3
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 3
- 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 3
- 239000000463 material Substances 0.000 description 3
- 239000007773 negative electrode material Substances 0.000 description 3
- -1 polytetrafluoroethylene Polymers 0.000 description 3
- 229910052777 Praseodymium Inorganic materials 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 229910052772 Samarium Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- VRAIHTAYLFXSJJ-UHFFFAOYSA-N alumane Chemical compound [AlH3].[AlH3] VRAIHTAYLFXSJJ-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- OJIJEKBXJYRIBZ-UHFFFAOYSA-N cadmium nickel Chemical compound [Ni].[Cd] OJIJEKBXJYRIBZ-UHFFFAOYSA-N 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 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
- 229920001155 polypropylene Polymers 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/383—Hydrogen absorbing alloys
-
- 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
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ネオジムとコバルトと
を含有するアルカリ蓄電池用の水素吸蔵合金に係わり、
詳しくは、容量と耐食性の物性バランスに優れた希土類
系水素吸蔵合金を得ることを目的とした、ネオジム及び
コバルトの全合金元素に対する各割合の規制に関する。TECHNICAL FIELD The present invention relates to a hydrogen storage alloy containing neodymium and cobalt for an alkaline storage battery,
More specifically, the present invention relates to regulation of respective ratios of neodymium and cobalt to all alloy elements for the purpose of obtaining a rare earth hydrogen storage alloy having an excellent balance of physical properties of capacity and corrosion resistance.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】近年、
正極に水酸化ニッケルなどの金属化合物を使用し、負極
に新素材の水素吸蔵合金を使用したアルカリ蓄電池が、
従前のニッケル−カドミウムアルカリ蓄電池に比し、軽
量化、高エネルギー密度化、高容量化が可能であるなど
の理由から、脚光を浴びつつある。2. Description of the Related Art In recent years,
An alkaline storage battery that uses a metal compound such as nickel hydroxide for the positive electrode and a new material hydrogen storage alloy for the negative electrode
Compared with the conventional nickel-cadmium alkaline storage battery, it is in the spotlight because it can be lighter in weight, higher in energy density, and higher in capacity.
【０００３】負極に使用する水素吸蔵合金の一つとし
て、ＡＢ5 型（Ａ成分：ミッシュメタルなどの希土類元
素の混合物、Ｂ成分：Ｎｉ、Ｃｏ、Ａｌ、Ｍｎ、Ｆｅな
ど）の希土類系水素吸蔵合金が提案されている。なかで
も、Ａ成分としてミッシュメタルを使用してなる水素吸
蔵合金は、ミッシュメタルが安価であることもあって、
アルカリ蓄電池用の負極材料として、特に有望視されて
いる材料の一つである。As one of the hydrogen storage alloys used for the negative electrode, a rare earth hydrogen storage alloy of AB 5 type (component A: a mixture of rare earth elements such as misch metal, component B: Ni, Co, Al, Mn, Fe, etc.). Alloys have been proposed. Among them, the hydrogen storage alloy made by using misch metal as the A component is because the misch metal is cheap,
It is one of the most promising materials as a negative electrode material for alkaline storage batteries.
【０００４】しかしながら、従来電池用として提案され
ているＡＢ5 型の希土類系水素吸蔵合金には、充放電サ
イクル寿命が短いという問題があった。However, the AB 5 type rare earth-based hydrogen storage alloys that have been conventionally proposed for batteries have a problem of short charge / discharge cycle life.
【０００５】本発明は、この問題を解決するべくなされ
たものであって、その目的とするところは、容量と耐食
性の物性バランスを改良することにより、アルカリ蓄電
池の負極として用いて好適な、充放電サイクル寿命が長
いＡＢ5 型の希土類系水素吸蔵合金を提供するにある。The present invention has been made to solve this problem, and an object thereof is to improve the balance between the physical properties of capacity and corrosion resistance, thereby making it suitable for use as a negative electrode of an alkaline storage battery. An object is to provide an AB 5 type rare earth hydrogen storage alloy having a long discharge cycle life.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するため
の本発明に係る希土類系水素吸蔵合金は、ネオジムとコ
バルトとを含有するＡＢ5 型（Ａ成分：少なくともネオ
ジム及びランタンを含む希土類元素の混合物でありアル
カリ土類元素を含んでいてもよい。；Ｂ成分：ニッケ
ル、及び、少なくともコバルトを含むニッケル置換元
素。）のアルカリ蓄電池用の希土類系水素吸蔵合金であ
って、前記ネオジム及び前記コバルトの全合金元素に対
する各割合が、それぞれ６〜１６重量％、及び、２〜１
０重量％であるものである。A rare earth hydrogen storage alloy according to the present invention for achieving the above object is an AB 5 type containing neodymium and cobalt (A component: a rare earth element containing at least neodymium and lanthanum). A rare earth-based hydrogen storage alloy for alkaline storage batteries, which is a mixture and may contain an alkaline earth element; B component: nickel, and a nickel substitution element containing at least cobalt. Of the total alloying elements of 6 to 16% by weight and 2-1 respectively
It is 0% by weight.
【０００７】ネオジム及びコバルトの全合金元素に対す
る好適な各割合は、それぞれ１０〜１４重量％、及び、
６〜８重量％である。因みに、従来電池用として提案さ
れている希土類系水素吸蔵合金は、ネオジムを５〜６重
量％程度、コバルトを１０〜１７重量量％程度の割合で
含有するものである。Suitable ratios of neodymium and cobalt to all alloying elements are 10 to 14% by weight, respectively, and
It is 6 to 8% by weight. Incidentally, the rare earth-based hydrogen storage alloy conventionally proposed for batteries contains neodymium in an amount of approximately 5 to 6% by weight and cobalt in an amount of approximately 10 to 17% by weight.
【０００８】本発明におけるＡＢ5 型の希土類系水素吸
蔵合金中のＡ成分としては、先に挙げたネオジム（Ｎ
ｄ）及びランタン（Ｌａ）の他、セリウム（Ｃｅ）、プ
ラセオジム（Ｐｒ）、サマリウム（Ｓｍ）、イットリウ
ム（Ｙ）、アルカリ土類元素がが例示され、また同Ｂ成
分としては、先に挙げたニッケル（Ｎｉ）及びコバルト
（Ｃｏ）の他、アルミウニム（Ａｌ）、マンガン（Ｍ
ｎ）、鉄（Ｆｅ）、銅（Ｃｕ）、珪素（Ｓｉ）が例示さ
れる。As the A component in the AB 5 type rare earth-based hydrogen storage alloy according to the present invention, neodymium (N
In addition to d) and lanthanum (La), cerium (Ce), praseodymium (Pr), samarium (Sm), yttrium (Y), and alkaline earth elements are exemplified, and the B component is the same as those mentioned above. In addition to nickel (Ni) and cobalt (Co), aluminum aluminum (Al), manganese (M
n), iron (Fe), copper (Cu), and silicon (Si) are exemplified.
【０００９】[0009]
【作用】全合金元素に対するネオジム及びコバルトの割
合がそれぞれ特定の範囲内に規制されているので、充放
電サイクル寿命が長くなる。この理由は次のとおりであ
る。[Function] Since the ratios of neodymium and cobalt with respect to all alloy elements are regulated within the respective specific ranges, the charge / discharge cycle life becomes long. The reason for this is as follows.
【００１０】負極材料たる希土類系水素吸蔵合金は充放
電サイクルの繰り返しに伴い酸化劣化するので、水素吸
蔵合金電極の実質容量は次第に低下する。この充放電サ
イクル経過後の実質容量が大きいものほど、充放電サイ
クル寿命が長くなる。この実質容量は下式で表される。Since the rare earth-based hydrogen storage alloy, which is the negative electrode material, is oxidized and deteriorated as the charge and discharge cycle is repeated, the substantial capacity of the hydrogen storage alloy electrode gradually decreases. The larger the actual capacity after the charge / discharge cycle has passed, the longer the charge / discharge cycle life becomes. This real capacity is expressed by the following formula.
【００１１】実質容量＝初期容量（初期の水素吸蔵量）
−酸化による容量低下分Real capacity = initial capacity (initial hydrogen storage capacity)
-Capacity loss due to oxidation
【００１２】従って、充放電サイクル経過後の実質容量
を大きくする、すなわち充放電サイクル寿命を長くする
ためには、初期容量を増大させるか、或いは酸化による
容量低下分を少なくすればよい。Therefore, in order to increase the actual capacity after the charging / discharging cycle, that is, to prolong the charging / discharging cycle life, the initial capacity may be increased or the capacity decrease due to oxidation may be decreased.
【００１３】ところで、本発明が対象とするネオジム及
びコバルトを含有する希土類系水素吸蔵合金の場合、ネ
オジム及びコバルトが高濃度に存在する結晶相と、ラン
タン、セリウム、マンガン、ニッケルなどが高濃度に存
在する結晶相とが偏析して存在している。ここにおい
て、前者の結晶相と後者の結晶相との元素濃度分布にお
ける濃淡が正反対に顕れることから、ネオジム及びコバ
ルトは、易酸化性のランタン及びマンガンの酸化（溶
解）を抑制する働きをしているものと思われる。By the way, in the case of the rare earth hydrogen storage alloy containing neodymium and cobalt, which is the object of the present invention, the crystal phase in which neodymium and cobalt are present in a high concentration, and lanthanum, cerium, manganese, nickel, etc. are present in a high concentration. The existing crystal phase is segregated and exists. Here, since the light and shade in the element concentration distribution of the former crystal phase and the latter crystal phase appear to be opposite to each other, neodymium and cobalt act to suppress the oxidation (dissolution) of oxidizable lanthanum and manganese. It seems that there is.
【００１４】事実、ランタンやマンガンの割合を小さく
するほど、すなわちネオジム及びコバルトの割合を相対
的に大きくするほど、耐食性（耐酸化性）は向上する。In fact, the smaller the proportion of lanthanum or manganese, that is, the larger the proportion of neodymium and cobalt, the higher the corrosion resistance (oxidation resistance).
【００１５】しかしながら、ランタンやマンガンの割合
を小さくするべく、ネオジム及びコバルトの割合を過剰
に大きくすることは、初期容量の低下を招く。すなわ
ち、初期容量が大きいものは酸化による容量低下分が大
きく、一方酸化による容量低下分が小さいものは逆に初
期容量が小さいという傾向があるのである。However, if the proportions of neodymium and cobalt are excessively increased in order to reduce the proportions of lanthanum and manganese, the initial capacity is lowered. That is, those having a large initial capacity tend to have a large capacity decrease due to oxidation, while those having a small capacity decrease due to oxidation tend to have a small initial capacity.
【００１６】そこで、ネオジム及びコバルトの全合金元
素に対する各割合を種々変えて充放電サイクル試験を行
ったところ、ネオジム及びコバルトの全合金元素に対す
る各割合が本発明で規制する特定の範囲にある場合に、
実質容量が大きい、すなわち充放電サイクル寿命が長い
希土類系水素吸蔵合金が得られることが分かった。これ
は、上式中の初期容量と酸化による容量低下分（耐食
性）の物性バランスが、全合金元素に対するネオジム及
びコバルトの割合を規制することにより、向上するため
と考えられる。Therefore, a charge-discharge cycle test was conducted by changing various ratios of neodymium and cobalt to all alloy elements, and when the ratios of neodymium and cobalt to all alloy elements were within a specific range regulated by the present invention. To
It was found that a rare earth-based hydrogen storage alloy having a large real capacity, that is, a long charge / discharge cycle life can be obtained. It is considered that this is because the balance of the physical properties of the initial capacity in the above formula and the capacity decrease (corrosion resistance) due to oxidation is improved by controlling the ratio of neodymium and cobalt to all alloy elements.
【００１７】[0017]
【実施例】以下、本発明を実施例に基づいてさらに詳細
に説明するが、本発明は下記実施例により何ら限定され
るものではなく、その要旨を変更しない範囲において適
宜変更して実施することが可能なものである。EXAMPLES The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by the examples described below, and various modifications may be made without departing from the scope of the invention. Is possible.
【００１８】〔希土類系水素吸蔵合金の作製〕高周波溶
解炉を用いて組成式（Ｌａa%Ｃｅb%Ｐｒ7%Ｎｄ
93-(a+b)% ）Ｎｉ4.3-x Ｃｏx Ａｌ0.3 Ｍｎ0.4 （％：
原子％）で表される希土類系水素吸蔵合金Ｎｏ．１〜Ｎ
ｏ．８０を作製した。なお、ランタンとセリウムとの重
量割合（ａ／ｂ）は全て０．６とした。作製した各希土
類系水素吸蔵合金中のＣｏ及びＮｄの全合金元素に対す
る各割合（重量％）を表１及び表２に示す。[Preparation of Rare Earth Hydrogen Storage Alloy] A composition formula (La a% Ce b% Pr 7% Nd) was prepared using a high frequency melting furnace.
93- (a + b)% ) Ni 4.3-x Co x Al 0.3 Mn 0.4 (%:
Rare earth hydrogen storage alloy No. 1 to N
o. 80 was produced. The weight ratios (a / b) of lanthanum and cerium were all set to 0.6. Tables 1 and 2 show the respective proportions (% by weight) of Co and Nd in all the produced rare earth-based hydrogen storage alloys with respect to all the alloying elements.
【００１９】[0019]
【表１】 [Table 1]
【００２０】[0020]
【表２】 [Table 2]
【００２１】〔水素吸蔵合金電極の作製〕各希土類系水
素吸蔵合金を、不活性ガス中で機械的に粉砕して、それ
ぞれ平均粒径１５０μｍの合金粉末とした。各合金粉末
１０ｇと、結着剤としてのＰＴＦＥ（ポリテトラフルオ
ロエチレン）の６０％水分散液０．８４ｇと、導電剤と
してのＰＥＯ（ポリエチレンオキシド）の５％水溶液１
ｇとを混合し、６０°Ｃ程度に加熱乾燥し、圧延して、
ペーストを作製した。次いで、このペーストから所定量
を切り出し、ニッケルメッシュで包み、加圧成形して直
径２０ｍｍの円板状の水素吸蔵合金電極を作製した。[Preparation of Hydrogen Storage Alloy Electrode] Each rare earth hydrogen storage alloy was mechanically pulverized in an inert gas to obtain an alloy powder having an average particle size of 150 μm. 10 g of each alloy powder, 0.84 g of 60% aqueous dispersion of PTFE (polytetrafluoroethylene) as a binder, and 5% aqueous solution of PEO (polyethylene oxide) as a conductive agent 1
g, heat dried to about 60 ° C, rolled,
A paste was made. Then, a predetermined amount was cut out from this paste, wrapped with a nickel mesh, and pressure-molded to produce a disk-shaped hydrogen storage alloy electrode having a diameter of 20 mm.
【００２２】〔試験セルの組立〕各水素吸蔵合金電極を
試験電極（負極）とし、当該試験電極に対して充分大き
な容量を持つニッケル極を対極として、試験セルＡ１〜
Ａ８０を組み立てた。なお、電解液として、３０重量％
の水酸化カリウム水溶液を用いた。[Assembly of Test Cell] Each of the hydrogen storage alloy electrodes was used as a test electrode (negative electrode), and a nickel electrode having a sufficiently large capacity for the test electrode was used as a counter electrode, and test cells A1 to
The A80 was assembled. As an electrolytic solution, 30% by weight
Was used.
【００２３】図１は、組み立てた試験セルの模式的斜視
図であり、図示の試験セル１は、円板状のペースト電極
（試験電極）２、試験電極よりも十分大きな電気化学容
量を持つ円筒状の焼結式ニッケル極（対極）３、絶縁性
の密閉容器（ポリプロピレン製）４などからなる。FIG. 1 is a schematic perspective view of the assembled test cell. The illustrated test cell 1 is a disk-shaped paste electrode (test electrode) 2 and a cylinder having an electrochemical capacity sufficiently larger than that of the test electrode. It is composed of a sintered nickel electrode (counter electrode) 3, a closed container (made of polypropylene) 4 having an insulating property, and the like.
【００２４】焼結式ニッケル極３は、密閉容器４の上面
６に接続された正極リード５により保持されており、ま
たペースト電極２は焼結式ニッケル極３の円筒内略中央
に垂直に位置するように、密閉容器４の上面６に接続さ
れた負極リード７により保持されている。The sintered nickel electrode 3 is held by a positive electrode lead 5 connected to the upper surface 6 of the hermetically sealed container 4, and the paste electrode 2 is positioned perpendicular to the substantially center of the sintered nickel electrode 3 in the cylinder. Thus, it is held by the negative electrode lead 7 connected to the upper surface 6 of the closed container 4.
【００２５】正極リード５及び負極リード７の各端部
は、密閉容器４の上面６を貫通して外部に露出し、それ
ぞれ正極端子５ａ及び負極端子７ａに接続されている。Each end of the positive electrode lead 5 and the negative electrode lead 7 penetrates the upper surface 6 of the closed container 4 and is exposed to the outside, and is connected to the positive electrode terminal 5a and the negative electrode terminal 7a, respectively.
【００２６】ペースト電極２及び焼結式ニッケル極３は
密閉容器４に入れられたアルカリ電解液（３０重量％水
酸化カリウム水溶液；図示せず）中に浸漬されており、
アルカリ電解液の上方空間部にはチッ素ガスが充填され
てペースト電極２に所定の圧力がかかるようにされてい
る。The paste electrode 2 and the sintered nickel electrode 3 are immersed in an alkaline electrolyte (30% by weight potassium hydroxide aqueous solution; not shown) contained in a closed container 4,
The upper space of the alkaline electrolyte is filled with nitrogen gas so that a predetermined pressure is applied to the paste electrode 2.
【００２７】また、密閉容器４の上面６の中央部には、
密閉容器４の内圧が所定圧以上に上昇するのを防止する
ために、圧力計８及びリリーフバルブ（逃し弁）９を備
えるリリーフ管１０が装着されている。Further, in the central portion of the upper surface 6 of the closed container 4,
In order to prevent the internal pressure of the closed container 4 from rising above a predetermined pressure, a pressure gauge 8 and a relief pipe 10 including a relief valve 9 are attached.
【００２８】〔充放電サイクル試験〕各試験セルについ
て、５０ｍＡ／ｇで８時間充電し、５分間休止した後、
５０ｍＡ／ｇで放電終止電圧１．０Ｖまで放電する工程
を１サイクルとする充放電サイクル試験を行い、各試験
電極の初期容量、耐食性及び充放電サイクル寿命を調べ
た。耐食性は、１００サイクル経過後の合金中の酸素濃
度（重量％）の逆数である耐食性指数で評価した。ま
た、充放電サイクル寿命は、放電容量が１００ｍＡｈ／
ｇに低下するまでのサイクル数で評価した。なお、酸素
濃度の測定は、試験電極中に含まれるポリオキシエチレ
ンを加熱分解させた後、行った。[Charge / Discharge Cycle Test] Each test cell was charged at 50 mA / g for 8 hours, and after resting for 5 minutes,
A charging / discharging cycle test in which one cycle is a process of discharging at a discharge end voltage of 1.0 V at 50 mA / g was performed, and the initial capacity, corrosion resistance, and charging / discharging cycle life of each test electrode were examined. The corrosion resistance was evaluated by the corrosion resistance index which is the reciprocal of the oxygen concentration (% by weight) in the alloy after 100 cycles. The charge / discharge cycle life is 100 mAh / discharge capacity.
The number of cycles until it decreased to g was evaluated. The oxygen concentration was measured after thermally decomposing polyoxyethylene contained in the test electrode.
【００２９】図２は、縦軸にコバルト量（全合金元素に
対する割合：重量％）を、また横軸にネオジム量（全合
金元素に対する割合：重量％）をとり、各コバルト量及
び各ネオジム量における容量を記載したグラフである。
なお、図中の破線は等容量線を示す。図２より、コバル
ト量及びネオジム量が多くなるほど容量が低下すること
が分かる。In FIG. 2, the vertical axis represents the cobalt content (ratio to all alloy elements: weight%), and the horizontal axis represents the neodymium content (ratio to total alloy elements: weight%). 3 is a graph showing the capacity of the battery.
In addition, the broken line in the figure shows an equal capacitance line. From FIG. 2, it can be seen that the capacity decreases as the amount of cobalt and the amount of neodymium increase.
【００３０】図３は、図２と同じ座標系に、各コバルト
量及び各ネオジム量における耐食性指数を記載したグラ
フである。なお、図中の破線は等耐食性指数線を示す。
図３より、コバルト量及びネオジム量が多くなるほど耐
食性が向上することが分かる。FIG. 3 is a graph showing the corrosion resistance index for each cobalt content and each neodymium content in the same coordinate system as in FIG. The broken line in the figure indicates the isocorrosion resistance index line.
From FIG. 3, it can be seen that the corrosion resistance improves as the cobalt content and the neodymium content increase.
【００３１】図４は、図２と同じ座標系に、各コバルト
量及び各ネオジム量における充放電サイクル寿命（回）
を記載したグラフである。なお、図４中の破線は等充放
電サイクル寿命線を示す。また、図５は、コバルト量が
全て８重量％と等しい水素吸蔵合金電極Ｎｏ．４１〜Ｎ
ｏ．５０の各充放電サイクル寿命を、縦軸に充放電サイ
クル寿命（回）をとり、横軸にネオジム量（全合金元素
に対する重量％）をとって示したグラフであり、さらに
図６は、ネオジム量が１２重量％と等しい水素吸蔵合金
電極Ｎｏ．６、Ｎｏ．１６、Ｎｏ．２６、Ｎｏ．３６、
Ｎｏ．４６、Ｎｏ．５６、Ｎｏ．６６、Ｎｏ．７６の各
充放電サイクル寿命を、縦軸に充放電サイクル寿命
（回）をとり、横軸にコバルト量（全合金元素に対する
重量％）をとって示したグラフである。FIG. 4 shows the same coordinate system as that of FIG. 2, and the charge / discharge cycle life (times) at each cobalt content and each neodymium content.
It is a graph which described. The broken line in FIG. 4 shows the equal charge / discharge cycle life line. In addition, in FIG. 41-N
o. 50 is a graph showing each charge / discharge cycle life of 50, the vertical axis represents the charge / discharge cycle life (times), and the horizontal axis represents the amount of neodymium (% by weight based on all alloy elements). Further, FIG. 6 shows neodymium. Hydrogen storage alloy electrode No. whose amount is equal to 12% by weight. 6, No. 16, No. 26, No. 36,
No. 46, No. 56, No. 66, No. 7 is a graph showing each charge / discharge cycle life of No. 76, in which the vertical axis represents the charge / discharge cycle life (times) and the horizontal axis represents the amount of cobalt (% by weight based on all alloy elements).
【００３２】図４〜図６より、ネオジム量については６
〜１６重量％、またコバルト量については２〜１０重量
％に規制することが、１１００回程度以上の長い充放電
サイクル寿命を有する水素吸蔵合金を得る上で必要であ
ることが分かる。From FIGS. 4 to 6, the amount of neodymium is 6
It is understood that it is necessary to control the content of cobalt to 16 wt% and the amount of cobalt to 2 to 10 wt% in order to obtain a hydrogen storage alloy having a long charge / discharge cycle life of about 1100 times or more.
【００３３】上記実施例では、本発明に係る水素吸蔵合
金をニッケル−水素アルカリ蓄電池の負極材料として使
用する場合を例に挙げて説明したが、本発明に係る水素
吸蔵合金は広くアルカリ蓄電池の負極材料として使用し
得るものである。In the above embodiments, the case where the hydrogen storage alloy according to the present invention is used as a negative electrode material of a nickel-hydrogen alkaline storage battery has been described as an example. However, the hydrogen storage alloy according to the present invention is widely used as a negative electrode for alkaline storage batteries. It can be used as a material.
【００３４】[0034]
【発明の効果】本発明に係るＡＢ5 型の希土類系水素吸
蔵合金は、初期容量と耐食性の物性バランスに優れてい
るので、充放電サイクル寿命が長いなど、本発明は優れ
た特有の効果を奏する。INDUSTRIAL APPLICABILITY The AB 5 type rare earth-based hydrogen storage alloy according to the present invention has an excellent balance of physical properties such as initial capacity and corrosion resistance. Play.
【図１】実施例で組み立てた試験セルの模式的斜視図で
ある。FIG. 1 is a schematic perspective view of a test cell assembled in an example.
【図２】全合金元素に対するコバルト量及びネオジム量
の割合と、容量との関係を示すグラフである。FIG. 2 is a graph showing the relationship between the capacity and the ratio of the amount of cobalt and the amount of neodymium to all alloy elements.
【図３】全合金元素に対するコバルト量及びネオジム量
の割合と、耐食性との関係を示すグラフである。FIG. 3 is a graph showing the relationship between the proportion of cobalt and neodymium with respect to all alloy elements and corrosion resistance.
【図４】全合金元素に対するコバルト量及びネオジム量
の割合と、充放電サイクル寿命との関係を示すグラフで
ある。FIG. 4 is a graph showing the relationship between the ratio of the amount of cobalt and the amount of neodymium to all alloy elements and the charge / discharge cycle life.
【図５】全合金元素に対するネオジム量の割合（コバル
ト量：一定）と、充放電サイクル寿命との関係を示すグ
ラフである。FIG. 5 is a graph showing the relationship between the ratio of the amount of neodymium to all alloy elements (cobalt amount: constant) and the charge / discharge cycle life.
【図６】全合金元素に対するコバルト量の割合（ネオジ
ム量：一定）と、充放電サイクル寿命との関係を示すグ
ラフである。FIG. 6 is a graph showing the relationship between the ratio of the amount of cobalt to all alloy elements (neodymium amount: constant) and the charge / discharge cycle life.
Claims (3)
（Ａ成分：少なくともネオジム及びランタンを含む希土
類元素の混合物でありアルカリ土類元素を含んでいても
よい。；Ｂ成分：ニッケル、及び、少なくともコバルト
を含むニッケル置換元素。）のアルカリ蓄電池用の希土
類系水素吸蔵合金であって、前記ネオジム及び前記コバ
ルトの全合金元素に対する各割合が、それぞれ６〜１６
重量％、及び、２〜１０重量％であることを特徴とする
アルカリ蓄電池用の希土類系水素吸蔵合金。1. An AB 5 type containing neodymium and cobalt (A component: a mixture of rare earth elements containing at least neodymium and lanthanum and may contain an alkaline earth element. B component: nickel, and A nickel-substituting element containing at least cobalt) for use in alkaline storage batteries, wherein the ratio of neodymium and cobalt to all alloy elements is 6 to 16 respectively.
% And 2 to 10% by weight, a rare earth hydrogen storage alloy for alkaline storage batteries.
素に対する各割合が、それぞれ１０〜１４重量％、及
び、６〜８重量％である請求項１記載のアルカリ蓄電池
用の希土類系水素吸蔵合金。2. The rare earth-based hydrogen storage alloy for alkaline storage batteries according to claim 1, wherein the respective proportions of the neodymium and the cobalt with respect to the total alloy elements are 10 to 14% by weight and 6 to 8% by weight, respectively.
項１又は２記載のアルカリ蓄電池用の希土類系水素吸蔵
合金。3. The rare earth hydrogen storage alloy for alkaline storage batteries according to claim 1, which contains manganese as the B component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23555893A JP3322452B2 (en) | 1993-08-27 | 1993-08-27 | Rare earth hydrogen storage alloy for alkaline storage batteries |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23555893A JP3322452B2 (en) | 1993-08-27 | 1993-08-27 | Rare earth hydrogen storage alloy for alkaline storage batteries |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0762475A true JPH0762475A (en) | 1995-03-07 |
| JP3322452B2 JP3322452B2 (en) | 2002-09-09 |
Family
ID=16987769
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
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| Country | Link |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2021044062A (en) * | 2019-09-06 | 2021-03-18 | トヨタ自動車株式会社 | Water-based battery |
-
1993
- 1993-08-27 JP JP23555893A patent/JP3322452B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2021044062A (en) * | 2019-09-06 | 2021-03-18 | トヨタ自動車株式会社 | Water-based battery |
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| Publication number | Publication date |
|---|---|
| JP3322452B2 (en) | 2002-09-09 |
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