JPH07111885B2 - Metal oxide-hydrogen storage battery and manufacturing method thereof - Google Patents
Metal oxide-hydrogen storage battery and manufacturing method thereofInfo
- Publication number
- JPH07111885B2 JPH07111885B2 JP62224308A JP22430887A JPH07111885B2 JP H07111885 B2 JPH07111885 B2 JP H07111885B2 JP 62224308 A JP62224308 A JP 62224308A JP 22430887 A JP22430887 A JP 22430887A JP H07111885 B2 JPH07111885 B2 JP H07111885B2
- Authority
- JP
- Japan
- Prior art keywords
- particles
- hydrogen storage
- battery
- negative electrode
- storage alloy
- 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.)
- Expired - Lifetime
Links
- 238000003860 storage Methods 0.000 title claims description 70
- 239000001257 hydrogen Substances 0.000 title claims description 68
- 229910052739 hydrogen Inorganic materials 0.000 title claims description 68
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 239000002184 metal Substances 0.000 title claims description 5
- 229910052751 metal Inorganic materials 0.000 title claims description 5
- 239000002245 particle Substances 0.000 claims description 111
- 229910045601 alloy Inorganic materials 0.000 claims description 75
- 239000000956 alloy Substances 0.000 claims description 75
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 66
- 150000004678 hydrides Chemical class 0.000 claims description 16
- 229910044991 metal oxide Inorganic materials 0.000 claims description 7
- 150000004706 metal oxides Chemical class 0.000 claims description 7
- 239000011246 composite particle Substances 0.000 claims description 6
- 239000011162 core material Substances 0.000 claims description 4
- 239000011230 binding agent Substances 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 2
- 239000003792 electrolyte Substances 0.000 claims description 2
- 238000004898 kneading Methods 0.000 claims 1
- 238000003825 pressing Methods 0.000 claims 1
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 12
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 11
- 229910001882 dioxygen Inorganic materials 0.000 description 11
- 239000000203 mixture Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 239000010419 fine particle Substances 0.000 description 6
- 239000002131 composite material Substances 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 239000008187 granular material Substances 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- 239000010409 thin film Substances 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 229910018502 Ni—H Inorganic materials 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 239000008151 electrolyte solution Substances 0.000 description 3
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 239000001768 carboxy methyl cellulose Substances 0.000 description 2
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 2
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 2
- 238000006356 dehydrogenation reaction Methods 0.000 description 2
- 238000005538 encapsulation Methods 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 238000005984 hydrogenation reaction Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000002715 modification method Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910001122 Mischmetal Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 238000007772 electroless plating Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229920000609 methyl cellulose Polymers 0.000 description 1
- 239000001923 methylcellulose Substances 0.000 description 1
- 239000011859 microparticle Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 239000000126 substance Substances 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
- H01M4/24—Electrodes for alkaline accumulators
- H01M4/242—Hydrogen storage electrodes
-
- 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)
- Battery Electrode And Active Subsutance (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は水素を可逆的に吸蔵・放出する合金又は水素化
物からなる電極、すなわち水素吸蔵電極を負極とし、金
属酸化物電極を正極とする金属酸化物−水素蓄電池とそ
の製造方法に関するもので、特に負極の改良に関するも
のである。TECHNICAL FIELD The present invention relates to a metal oxide in which an electrode made of an alloy or a hydride that reversibly stores and releases hydrogen, that is, a hydrogen storage electrode serves as a negative electrode and a metal oxide electrode serves as a positive electrode. Battery-hydrogen storage battery and a method of manufacturing the same, and more particularly, to an improvement of a negative electrode.
従来の技術 従来、この種の水素吸蔵電極を負極とする金属酸化物−
水素蓄電池では、充・放電サイクルの繰り返しによって
負極を構成する水素吸蔵合金又は水素化物粒子が細分化
し、しかも膨張により亀裂を発生し電極支持体から脱落
するなどの理由で電池性能の低下がおこる。この現象は
とくに開放形アルカリ蓄電池に顕著に現われる。そこで
水素吸蔵合金粒子の表面を銅の薄膜で完全に被覆する試
みが提案されている（特開昭50−111546号公報）。水素
吸蔵合金又は水素化物粒子の表面に銅を無電解メッキす
るなどにより、完全に被覆膜を形成し、電極自体の耐久
性を図っている。2. Description of the Related Art Conventionally, a metal oxide having this kind of hydrogen storage electrode as a negative electrode
In a hydrogen storage battery, the battery performance deteriorates because the hydrogen storage alloy or the hydride particles constituting the negative electrode are subdivided by repeated charge / discharge cycles, and cracks are generated due to expansion and fall off from the electrode support. This phenomenon is particularly noticeable in open alkaline storage batteries. Therefore, an attempt to completely coat the surface of the hydrogen storage alloy particles with a copper thin film has been proposed (Japanese Patent Laid-Open No. 50-111546). The surface of the hydrogen-absorbing alloy or hydride particles is electrolessly plated with copper to form a complete coating film to improve the durability of the electrode itself.
発明が解決しようとする問題点 この様な従来の構成では負極自体の機械的強度と導電性
は改良されるが、その反面水素吸蔵合金又は水素化物粒
子の表面が金属薄膜で完全に被覆されるので、水素を電
気化学的に吸蔵・放出する速度が遅く、しかも水素吸蔵
量が減少する。このために電池性能が低下する。また、
密閉形蓄電池を構成した場合、過充電時正極で発生する
酸素ガスを負極表面で還元反応により水にする必要があ
るが、酸素ガスの発生より消費する反応がおくれ、電池
内に酸素ガスが蓄積して電池内圧を上昇させる。とく
に、急速充電時において、この現象が顕著に現われ、安
全性の点でも問題となる。Problems to be Solved by the Invention Although the mechanical strength and conductivity of the negative electrode itself are improved in such a conventional structure, the surface of the hydrogen storage alloy or hydride particles is completely covered with the metal thin film. Therefore, the rate of electrochemically absorbing and desorbing hydrogen is slow, and the hydrogen storage amount is reduced. Therefore, the battery performance is reduced. Also,
When a sealed storage battery is configured, the oxygen gas generated at the positive electrode during overcharge needs to be converted into water by the reduction reaction on the negative electrode surface, but the reaction that consumes the oxygen gas is delayed, and the oxygen gas accumulates in the battery. Then, the internal pressure of the battery is increased. In particular, this phenomenon appears remarkably during rapid charging, which poses a problem in terms of safety.
そこで、本発明はこのような問題点を解決するもので、
高率放電特性に優れ、過充電時に正極より発生する酸素
ガスを負極表面で高率良く吸収させ、電池の内圧上昇の
抑制と充・放電サイクル寿命の伸長を図ることを目的と
するものである。Therefore, the present invention solves such problems,
It has excellent high-rate discharge characteristics, and aims to absorb the oxygen gas generated from the positive electrode during overcharge with high efficiency on the negative electrode surface, to suppress the increase in the internal pressure of the battery and to extend the life of the charge / discharge cycle. .
問題点を解決するための手段 この問題点を解決するために、本発明は金属酸化物正極
と、水素吸蔵合金又は水素化物からなる負極と、セパレ
ータおよびアルカリ性電解液を備え、前記負極を構成す
る水素吸蔵合金粒子（母粒子）又は水素化物粒子（母粒
子）の表面を少なくとも前記母粒子よりも細かい同合金
粒子又は水素化物粒子（子粒子）が部分的に被覆してい
るものである。Means for Solving the Problems In order to solve this problem, the present invention comprises a metal oxide positive electrode, a negative electrode made of a hydrogen storage alloy or a hydride, a separator and an alkaline electrolyte, and constitutes the negative electrode. The surface of the hydrogen storage alloy particles (mother particles) or the hydride particles (mother particles) is partially covered with at least the alloy particles or hydride particles (child particles) smaller than the mother particles.
また、母粒子の表面を前記母粒子より細かい同合金粒子
又は水素化物粒子（子粒子）によって部分的に被覆され
ている複合粒体を不活性雰囲気中でバインダーと共に十
分混練（混合・撹拌）してペースト状とし、さらにこの
ペーストを芯材の両面に塗着、あるいは多孔体内に充て
んし、加圧後、乾燥して負極とする製造方法によるもの
である。Further, the composite particles in which the surfaces of the mother particles are partially covered with the same alloy particles or hydride particles (child particles) finer than the mother particles are sufficiently kneaded (mixed / stirred) with a binder in an inert atmosphere. To form a paste, and the paste is applied to both surfaces of the core material or filled in a porous body, pressurized, and then dried to obtain a negative electrode.
作 用 このような構成により比表面積の大きい水素吸蔵合金微
粒子（子粒子）又は水素化物微粒子（子粒子）が同様な
水素吸蔵合金粒子（母粒子）又は水素化物粒子（母粒
子）の表面で強固に結合している形状で、一種の複合粒
体を形成しているので、母粒子全体の表面積が大きくな
り、過充電時に正極から発生する酸素ガスを負極で吸収
する触媒作用も大きく向上し、電池内圧力の上昇を抑制
し、充・放電サイクル寿命を伸長することとなる。Due to such a structure, hydrogen storage alloy fine particles (child particles) or hydride fine particles (child particles) having a large specific surface area are firmly adhered on the surface of similar hydrogen storage alloy particles (mother particles) or hydride particles (mother particles). In the shape of being bonded to, forming a kind of composite particles, the surface area of the entire mother particles is increased, the catalytic action of absorbing oxygen gas generated from the positive electrode at the time of overcharge in the negative electrode is also greatly improved, This will suppress the rise in battery pressure and extend the charge / discharge cycle life.
実施例 実施例１ 市販のMm（ミッシュメタル）、La,Ni,Coを一定の組成比
に秤量した試料をアーク溶解法により加熱溶解させた。
その一例として、合金組成であるMm0.4La0.6Ni3.7Co0.3
を負極用の水素吸蔵合金とした。この合金を粉砕機で37
μｍ以下まで粉砕し水素吸蔵合金粉体（母粒子）とし
た。ついで同じ組成の水素吸蔵合金を不活性雰囲気中で
さらに0.1〜３μｍ程度まで細分化して微粒子（子粒
子）とし、この微粒子（子粒子）を先の母粒子の表面に
部分的に形成させて水素吸蔵合金粒子（母粒子）の表面
改質を行なった。さらに不活性雰囲気中においてこの複
合粒体に0.5％程度のメチルセルロース溶液を適量加
え、十分混練（混合撹拌）し、ペースト状とした。この
ペーストをパンチングメタルの様な導電性の優れている
芯材の両面に塗着し、乾燥後最適な厚さに加工した後、
一定の大きさに裁断した電極基板にリード板を取付け負
極とした。この負極を用いた密閉形蓄電池をＡとする。Example 1 A sample in which commercially available Mm (Misch metal), La, Ni, and Co were weighed at a constant composition ratio was heated and melted by an arc melting method.
As an example, an alloy composition of Mm 0.4 La 0.6 Ni 3.7 Co 0.3
Was used as a hydrogen storage alloy for the negative electrode. Grind this alloy 37
The particles were pulverized to a size of not more than μm to obtain a hydrogen storage alloy powder (base particles). Then, a hydrogen storage alloy of the same composition is further subdivided into particles (sub-particles) in an inert atmosphere to about 0.1 to 3 μm, and the micro-particles (sub-particles) are partially formed on the surface of the mother particles to form hydrogen. The surface of the storage alloy particles (base particles) was modified. Further, an appropriate amount of about 0.5% methylcellulose solution was added to the composite granules in an inert atmosphere and sufficiently kneaded (mixed and stirred) to form a paste. After applying this paste to both sides of a core material with excellent conductivity such as punching metal, after drying and processing to an optimum thickness,
A lead plate was attached to an electrode substrate cut into a certain size to make a negative electrode. A sealed storage battery using this negative electrode is designated as A.
実施例２ 実施例１と同様な製法により、合金組成であるMm0.4La
0.6Ni3.7Co0.3を負極用の水素吸蔵合金とし、この合金
を粉砕機で37μｍ以下まで粉砕し水素吸蔵合金粉体（母
粒子）とした。ついでTi2Niの合金組成を持つ水素吸蔵
合金を水素雰囲気中で水素化と脱水素化を交互に行なわ
せ、微細化と活性化を同時に行なわせ、0.05〜３μｍ程
度まで微細化した微粒子（子粒子）を先の母粒子の表面
に部分的に形成させて水素吸蔵合金粒子（母粒子）の表
面改質を行なった。さらに、不活性雰囲気中において、
この複合粒体に0.5％程度のCMC（カルボキシメチルセル
ロース）溶液を適量加え、よく混練（混合撹拌）しペー
スト状とした。このペーストを発泡状ニッケル多孔体内
に充てんし、乾燥後最適な厚さに加圧した後、一定の大
きさに裁断した電極基板にリード板を取付け負とした。
この負極を用いた密閉形蓄電池をＢとする。Example 2 By the same manufacturing method as in Example 1, the alloy composition Mm 0.4 La
0.6 Ni 3.7 Co 0.3 was used as the hydrogen storage alloy for the negative electrode, and this alloy was pulverized to 37 μm or less with a pulverizer to obtain hydrogen storage alloy powder (base particles). Then, a hydrogen storage alloy having an alloy composition of Ti 2 Ni is subjected to alternating hydrogenation and dehydrogenation in a hydrogen atmosphere to be refined and activated at the same time. Particles) were partially formed on the surface of the mother particles to reform the surface of the hydrogen storage alloy particles (mother particles). Furthermore, in an inert atmosphere,
An appropriate amount of CMC (carboxymethyl cellulose) solution of about 0.5% was added to the composite granules, and they were well kneaded (mixed and stirred) to form a paste. This paste was filled in a foamed nickel porous body, dried and pressed to an optimum thickness, and then a lead plate was attached to a negative electrode substrate, which was cut into a certain size, to make it negative.
Let B be a sealed storage battery using this negative electrode.
ここで、水素吸蔵合金粒子（母粒子）の表面改質に用い
た方法の１例として「化学装置」1986年９月号（P.19）
記載の粉体の表面改質方法を採用した。この表面改質法
（高速気流中衝撃カプセル化）は水素吸蔵合金粒子の表
面に静電気的に水素吸蔵合金粒子（微粒子）を付着させ
る。この状態では水素吸蔵合金粒子間での結合力が弱
く、両粒子が脱離するので、さらに水素吸蔵合金粒子か
らなる複合粉体を回転ドラム中で高速気流によって回転
させて、水素吸蔵合金粒子の表面にさらに微細な水素吸
蔵合金粒子を高速気流の応力による水素吸蔵合金（母粒
子）相互の衝突によって、打ち込むように水素吸蔵合金
同志に衝撃を与え、強固に水素吸蔵合金の微粒子（子粒
子）を部分的に被覆した水素吸蔵合金の複合粉体を作る
ことができる。Here, as an example of the method used for surface modification of hydrogen storage alloy particles (base particles), "Chemical apparatus" September 1986 issue (P.19)
The powder surface modification method described was adopted. In this surface modification method (impact encapsulation in high-speed air flow), hydrogen storage alloy particles (fine particles) are electrostatically attached to the surface of the hydrogen storage alloy particles. In this state, the binding force between the hydrogen-absorbing alloy particles is weak and both particles are desorbed, so further rotating the composite powder consisting of the hydrogen-absorbing alloy particles by the high-speed air flow in the rotating drum, Finer hydrogen-absorbing alloy particles on the surface impact the hydrogen-absorbing alloys (mother particles) with each other by collision of the hydrogen-absorbing alloys (mother particles) due to the stress of the high-speed air flow, and impact the hydrogen-absorbing alloys with each other to firmly and firmly It is possible to produce a composite powder of a hydrogen storage alloy partially covered with.
また、比較のために、水素吸蔵合金粒子の表面に、公知
の無電解メッキ法によって、銅の薄膜を形成させた試料
を用い、その他は実施例１と同じ製法で水素吸蔵電極を
試作し、リード板を取付け負極とした。この負極を用い
た密閉形蓄電池をＣとする。For comparison, a sample having a copper thin film formed on the surface of the hydrogen-absorbing alloy particles by a known electroless plating method was used, and a hydrogen-absorbing electrode was manufactured as a trial by the same manufacturing method as in Example 1, A lead plate was attached to serve as a negative electrode. Let C be a sealed storage battery using this negative electrode.
水素吸蔵合金は正極の公称容量の1.5倍である全量15gを
用いた。公知の発泡状ニッケル正極とセパレータを介し
て公称2Ahの密閉形Ni−H2蓄電池を構成し、放電容量特
性と充・放電サイクル寿命特性を測定した。As the hydrogen storage alloy, a total amount of 15 g, which is 1.5 times the nominal capacity of the positive electrode, was used. A sealed Ni-H 2 storage battery having a nominal capacity of 2 Ah was constructed through a known foamed nickel positive electrode and a separator, and the discharge capacity characteristics and charge / discharge cycle life characteristics were measured.
第１図に微細な水素吸蔵合金粒子で表面改質した水素吸
蔵合金の構造を示し、第２図には第１図の水素吸蔵合金
を負極とする密閉形Ni−H2蓄電池を示す。Fig. 1 shows the structure of a hydrogen storage alloy surface-modified with fine hydrogen storage alloy particles, and Fig. 2 shows a sealed Ni-H 2 storage battery having the hydrogen storage alloy of Fig. 1 as a negative electrode.
第１図において（Ｉ）は水素吸蔵合金粒子（母粒子）１
の表面に微細な水素吸蔵合金粒子（子粒子）２が単に静
電付着したモデル図であり、（II）は高速気流中での衝
撃カプセル化法によって、水素吸蔵合金粒子（母粒子）
３の表面から微細な水素吸蔵合金粒子（子粒子）４が一
部内部に食い込んで強固に結合し、表面積の拡大を図っ
た状態を示したものである。In FIG. 1, (I) is a hydrogen storage alloy particle (mother particle) 1
Is a model diagram in which fine hydrogen-absorbing alloy particles (child particles) 2 are simply electrostatically adhered to the surface of, and (II) is a hydrogen-absorbing alloy particle (mother particle) by impact encapsulation method in a high-speed air flow.
3 shows a state in which fine hydrogen-absorbing alloy particles (child particles) 4 partly penetrate into the inside of the surface of 3 and are firmly bonded to each other to increase the surface area.
第２図において、水素吸蔵合金からなる負極５とニッケ
ル正極６は、セパレータ７を介して渦巻き状に巻回さ
れ、負極端子を兼ねるケース８に挿入される。なお極板
群の上，下は絶縁板9,10が当てがわれ、安全弁11のある
封口板12でケース８の開口部は密閉化されている。13は
封口板12を介して正極リード14と接続したキャップ状の
正極端子である。なお充電時に負極からの水素発生を抑
制するために正極容量より負極容量を大きくし正極律則
とした。電池の充・放電条件として0.2C（400mA）で7.5
時間充電（150％充電）し、0.2C（400mA）で放電した。
充・放電サイクル試験の温度はすべて20℃とし、終止電
圧は1.0Vとした。その充・放電サイクルと放電容量の関
係を第３図に示し、また充・放電を10サイクル繰り返え
した後において、電池の150％充電時までにおける電池
内圧の変化を第４図に示す。In FIG. 2, a negative electrode 5 made of a hydrogen storage alloy and a nickel positive electrode 6 are spirally wound via a separator 7 and inserted in a case 8 which also serves as a negative electrode terminal. Insulating plates 9 and 10 are applied to the upper and lower sides of the electrode plate group, and the opening of the case 8 is sealed by a sealing plate 12 having a safety valve 11. Reference numeral 13 is a cap-shaped positive electrode terminal connected to the positive electrode lead 14 via the sealing plate 12. In order to suppress the generation of hydrogen from the negative electrode during charging, the negative electrode capacity was made larger than the positive electrode capacity, and the positive electrode law was adopted. 7.5 at 0.2C (400mA) as battery charge / discharge conditions
Charged for 150 hours (charged 150%) and discharged at 0.2C (400mA).
The temperature of the charge / discharge cycle test was 20 ° C., and the final voltage was 1.0V. The relationship between the charge / discharge cycle and the discharge capacity is shown in FIG. 3, and the change in battery internal pressure up to 150% charge of the battery after charge / discharge is repeated 10 cycles is shown in FIG.
第３図からわかる様に従来形電池Ｃの放電容量は充・放
電50サイクルまでは正極容量である2Ahをほぼ維持して
いるが、約75サイクル後から急激に低下している。この
低下原因は充・放電サイクルの増加と共に電池内圧が上
昇し、安全弁の作動圧力である10kg/cm2を約75サイクル
の所で越えており、安全弁より過充電時に発生する酸素
ガスや水素ガスが排出し、また一部電解液の漏出も発生
して、電池内の電解液が減少し、このために電池の内部
抵抗が増大し、容量低下を引き起こしていると考えられ
る。この事は第４図に示す充電率と電池内圧の関係から
も容易に推際出来る。充・放電10サイクル後の過充電特
性からも明らかな様に、従来形電池Ｃは充電率75％附近
から一部水素発生があり、充電率100％を越えると正極
から発生する酸素ガスのために電池内圧が上昇してい
る。充電率150％では約9kg/cm2まで電池内圧の上昇が見
られる。したがって、さらに充・放電サイクルが増加す
ると当然、充電率150％における電池内圧は安全弁の作
動圧力である10kg/cm2を越えてしまう。この様に従来形
電池Ｃは、水素ガスの蓄積による内圧と正極から発生す
る酸素ガスの内圧が加算されて、高い電池内圧力を示し
ている。この事は負極を構成する水素吸蔵合金粒子の表
面で、正極から発生するガスを効率よく吸収する能力が
不足しているためである。即ち、水素吸蔵合金粒子の表
面が金属薄膜で被覆されているために、粒子自体の表面
積が小さく、酸素ガスとの反応性を抑制しているものと
考えられる。As can be seen from FIG. 3, the discharge capacity of the conventional battery C is maintained at 2 Ah, which is the positive electrode capacity, up to 50 cycles of charge and discharge, but it rapidly decreases after about 75 cycles. The cause of this decrease is that the internal pressure of the battery rises as the charge / discharge cycle increases, and the operating pressure of the safety valve, 10 kg / cm 2 , is exceeded at about 75 cycles.Therefore, oxygen gas and hydrogen gas generated during overcharge from the safety valve It is conceivable that some of the electrolyte solution is discharged and some of the electrolyte solution leaks, and the electrolyte solution in the battery decreases, which increases the internal resistance of the battery and causes the capacity to decrease. This can be easily inferred from the relationship between the charging rate and the battery internal pressure shown in FIG. As is clear from the overcharge characteristics after 10 cycles of charging / discharging, the conventional battery C partially generates hydrogen around the charging rate of 75%, and when the charging rate exceeds 100%, it is oxygen gas generated from the positive electrode. The battery pressure is rising. At a charge rate of 150%, the internal pressure of the battery rises up to about 9 kg / cm 2 . Therefore, when the charging / discharging cycle is further increased, the battery internal pressure at the charging rate of 150% naturally exceeds the operating pressure of the safety valve, which is 10 kg / cm 2 . As described above, the conventional battery C exhibits a high battery internal pressure by adding the internal pressure due to the accumulation of hydrogen gas and the internal pressure of the oxygen gas generated from the positive electrode. This is because the surface of the hydrogen storage alloy particles constituting the negative electrode lacks the ability to efficiently absorb the gas generated from the positive electrode. That is, it is considered that since the surface of the hydrogen storage alloy particles is covered with the metal thin film, the surface area of the particles themselves is small and the reactivity with oxygen gas is suppressed.
これに対して本発明形電池は充・放電サイクルの増加と
共に放電容量の減少も殆んどなく、300サイクルに達し
ても1.9〜2.0Ahを保持し、従来形電池のような負極によ
る性能低下は見られない。これは、第４図からもわかる
ように従来形電池と異なり過充電時の電池内圧を見て
も、電池内圧の上昇は比較的小さく、充・放電10サイク
ルでは最大4kg/cm2程度であり、電池内の水素ガスの蓄
積を非常に少ない。また、300サイクルに達しても、安
全弁からの漏液現象も観察されない事から、電池内圧力
は10kg/cm2以下を保持し、安全弁からの酸素ガスや水素
ガスの排出もなく、過充電時には正極から発生した酸素
ガスは負極において効率よく吸収され、再び水に還元さ
れているものと考えられる。この様に過充電においても
電池内圧の急激な上昇が見られないのは、第１図に示す
ように、水素吸蔵合金粒子（母粒子）の表面にさらに微
細な水素吸蔵合金粒子（子粒子）を強固に結合・形成し
ているために、水素吸蔵合金全体の表面積が非常に大き
くなり、酸素ガスを吸収する能力が大幅に向上している
ためである。On the other hand, the battery of the present invention shows almost no decrease in discharge capacity as the number of charge / discharge cycles increases, and holds 1.9 to 2.0 Ah even after reaching 300 cycles. Can't be seen. As can be seen from Fig. 4, this is different from the conventional type battery, and the internal pressure of the battery during overcharging is relatively small, and the maximum increase is about 4 kg / cm 2 in 10 cycles of charging and discharging. , Very little accumulation of hydrogen gas in the battery. In addition, even after reaching 300 cycles, no liquid leakage from the safety valve was observed.Therefore, the internal pressure of the battery was kept below 10 kg / cm 2 and no oxygen or hydrogen gas was discharged from the safety valve. It is considered that the oxygen gas generated from the positive electrode is efficiently absorbed in the negative electrode and is reduced to water again. As shown in FIG. 1, the hydrogen storage alloy particles (mother particles) have finer hydrogen storage alloy particles (child particles) on the surface thereof. This is because the surface area of the entire hydrogen storage alloy is very large and the ability to absorb oxygen gas is greatly improved because the hydrogen is strongly bonded and formed.
しかも、母粒子と子粒子が強固に係合すると共に、その
両者からなる複合粒体が相互に結合し合って、電極自体
の強度、導電性も向上しており、充・放電サイクル寿命
に良い効果を与えている。Moreover, the mother particles and the child particles are firmly engaged with each other, and the composite particles composed of the both particles are bonded to each other to improve the strength and conductivity of the electrode itself, which is good for the charge / discharge cycle life. Giving effect.
第３図，第４図に従来形電池Ｃと比較して本発明形電池
A,Bの特性を各々示しているが、本発明形電池Ａは母粒
子と子粒子に用いた水素吸蔵合金を同じ組成としたもの
であり、本発明形電池Ｂは母粒子と子粒子に用いた水素
吸蔵合金を異なる材料としたものであるが、いずれも同
じ様な性能が得られている。負極に用いる水素吸蔵合金
はその種類，組成によって、各種特性も異なって来る
が、水素吸蔵合金粒子単独よりは本発明形電池に用いる
様な水素吸蔵合金粒子（母粒子）の面を微細な水素吸蔵
合金（子粒子）で改質した表面積の大きい複合粒体を用
いる法が過充電特性、サイクル寿命特性共向上する。The battery of the present invention is compared with the conventional battery C in FIGS.
The characteristics of A and B are respectively shown. The battery A of the present invention has the same composition as the hydrogen storage alloy used for the mother particles and the child particles, and the battery B of the present invention has the same composition for the mother particles and the daughter particles. The hydrogen storage alloys used are different materials, but all have similar performance. The hydrogen storage alloy used for the negative electrode has various characteristics depending on its type and composition. However, the surface of the hydrogen storage alloy particles (base particles) used in the battery of the present invention is finer than the hydrogen storage alloy particles alone. The method using a composite particle with a large surface area modified by a storage alloy (child particles) improves both overcharge characteristics and cycle life characteristics.
本実施例では母粒子となる水素吸蔵合金を機械的に粉砕
した粒体を用いたが、水素吸蔵合金を水素化させて細分
化した水素化物を用いることも出来る。水素化した粒体
を脱水素化した状態で負極を作り、密閉形Ni−H2蓄電池
を構成し、充・放電サイクル寿命を調べたが同様な特性
を得ている。当然、水素吸蔵合金を水素化と脱水素化を
繰り返えして微細化した微粒子を子粒子として用いる
と、より細かい微粒子が製造出来るので、有効な方法で
はあるが、この微粒子は非常に活性であり、酸化雰囲気
中で急激に酸化するので、空気中での操作が少し困難と
なる。そこで、実施例２で実施した様に、不活性ガス中
で製造した複合粒体を同様な不活性ガス中でバインダー
と混合しペースト状となし、そのペーストを芯材の両面
に塗着したり、発泡状多孔体内に充てんして水素吸蔵電
極とする方法は製造上安全性に優れ、水素吸蔵合金の微
粒子（子粒子）の急激な酸化を抑制する事が出来る。In the present embodiment, the granular particles obtained by mechanically crushing the hydrogen storage alloy to be the mother particles were used, but it is also possible to use a hydride obtained by hydrogenating the hydrogen storage alloy and subdividing it. The negative electrode was made in the state where the hydrogenated granules were dehydrogenated, a sealed Ni-H 2 storage battery was constructed, and the charge / discharge cycle life was examined, but similar characteristics were obtained. Naturally, fine particles obtained by repeating hydrogenation and dehydrogenation of a hydrogen storage alloy as fine particles can be used to produce finer particles, so this is an effective method, but these particles are very active. However, since it is rapidly oxidized in an oxidizing atmosphere, it becomes a little difficult to operate in air. Therefore, as in Example 2, the composite granules produced in an inert gas are mixed with a binder in the same inert gas to form a paste, and the paste is applied to both surfaces of the core material. The method of filling a foamed porous body to form a hydrogen storage electrode is excellent in manufacturing safety and can suppress rapid oxidation of fine particles (child particles) of the hydrogen storage alloy.
また、本実施例では水素吸蔵合金の１例としてMm0.4La
0.6Ni3.7Co0.3,Ti2Niを用いたが、他の水素吸蔵合金
（常温で水素平衡解離圧力0.05〜５気圧）でも同様な効
果が期待できる。第１図には水素吸蔵合金粒子（母粒
子）の表面に微細な水素吸蔵合金粒子（子粒子）が結合
しているモデル図を示しているが、１層だけでなく実際
には、部分的に２〜３層にも重なっている場合もありう
る。この様に多層に複合化した水素吸蔵合金粒体も同様
な効果が発揮される。Further, in this embodiment, as an example of the hydrogen storage alloy, Mm 0.4 La
Although 0.6 Ni 3.7 Co 0.3 and Ti 2 Ni were used, the same effect can be expected with other hydrogen storage alloys (hydrogen equilibrium dissociation pressure of 0.05 to 5 atm at room temperature). Fig. 1 shows a model diagram in which fine hydrogen-absorbing alloy particles (child particles) are bound to the surface of hydrogen-absorbing alloy particles (mother particles). There may be two or three layers overlapping. The hydrogen storage alloy particles that are composited in multiple layers in this way also exhibit similar effects.
発明の効果 以上の様に、本発明によれば、過充電時における安全性
が高く、しかも充・放電サイクル寿命の長い金属酸化物
・水素蓄電池であり、また安全性の高い製造方法を提供
できるという効果が得られる。EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to provide a highly safe manufacturing method which is a metal oxide / hydrogen storage battery having high safety during overcharge and having a long charge / discharge cycle life. The effect is obtained.
第１図は水素吸蔵合金粒子（母粒子）と微細な水素吸蔵
合金粒子（子粒子）の結合状態を示すモデル図、第２図
は微細な水素吸蔵合金粒子（子粒子）で表面改質した水
素吸蔵合金粒子（母粒子）からなる複合粒体を負極に用
いた密閉形ニッケル−水素蓄電池の斜視図、第３図は充
・放電サイクルと放電容量の関係において、従来形電池
と本発明形電池を比較した図、第４図は充電率と電池内
圧の関係において、従来形電池と本発明形電池を比較し
た図である。 1,3……水素吸蔵合金粒子（母粒子）、2,4……微細な水
素吸蔵合金粒子（子粒子）、５……負極板、６……正極
板、７……セパレータ。FIG. 1 is a model diagram showing the bonding state of hydrogen storage alloy particles (mother particles) and fine hydrogen storage alloy particles (child particles), and FIG. 2 is surface modification with fine hydrogen storage alloy particles (child particles). FIG. 3 is a perspective view of a sealed nickel-hydrogen storage battery using a composite particle composed of hydrogen-absorbing alloy particles (mother particles) as a negative electrode, and FIG. 3 shows the conventional battery and the present invention type in relation to charge / discharge cycle and discharge capacity. FIG. 4 is a diagram comparing the batteries, and FIG. 4 is a diagram comparing the conventional type battery and the present invention type battery in relation to the charging rate and the battery internal pressure. 1,3 …… Hydrogen storage alloy particles (mother particles), 2,4 …… Fine hydrogen storage alloy particles (child particles), 5 …… Negative electrode plate, 6 …… Positive electrode plate, 7 …… Separator.
Claims (2)
化物からなる負極と、セパレータおよびアルカリ性電解
液を備え、前記負極を構成する水素吸蔵合金粒子又は水
素化物粒子（母粒子）の表面は、少なくとも前記母粒子
よりも細かい同合金粒子又は水素化物粒子（子粒子）が
部分的に被覆されていることを特徴とする金属酸化物−
水素蓄電池。1. A metal oxide positive electrode, a negative electrode made of a hydrogen storage alloy or a hydride, a separator and an alkaline electrolyte, wherein the surface of the hydrogen storage alloy particles or hydride particles (mother particles) constituting the negative electrode is A metal oxide characterized in that at least the same alloy particles or hydride particles (child particles) finer than the mother particles are partially covered.
Hydrogen storage battery.
化物粒子（母粒子）の表面を前記母粒子より細かい同合
金粒子又は水素化物粒子（子粒子）によって部分的に被
覆した複合粒体を不活性雰囲気中でバインダーと共に十
分混練してペースト状とし、さらにこのペーストを芯材
の両面に塗着、あるいは多孔体内に充てんし、加圧後、
乾燥して負極とすることを特徴とする金属酸化物−水素
蓄電池の製造方法。2. A composite particle in which the surface of hydrogen storage alloy particles or hydride particles (mother particles) constituting a negative electrode is partially covered with the same alloy particles or hydride particles (child particles) smaller than the mother particles. After kneading with a binder in an inert atmosphere, a paste is formed, and the paste is applied to both sides of the core material or filled in a porous body, and after pressing,
A method for producing a metal oxide-hydrogen storage battery, which comprises drying to obtain a negative electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62224308A JPH07111885B2 (en) | 1987-09-08 | 1987-09-08 | Metal oxide-hydrogen storage battery and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62224308A JPH07111885B2 (en) | 1987-09-08 | 1987-09-08 | Metal oxide-hydrogen storage battery and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6467868A JPS6467868A (en) | 1989-03-14 |
| JPH07111885B2 true JPH07111885B2 (en) | 1995-11-29 |
Family
ID=16811728
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62224308A Expired - Lifetime JPH07111885B2 (en) | 1987-09-08 | 1987-09-08 | Metal oxide-hydrogen storage battery and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07111885B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2692936B2 (en) * | 1989-03-01 | 1997-12-17 | 三洋電機株式会社 | Hydrogen storage alloy electrode for alkaline storage battery |
-
1987
- 1987-09-08 JP JP62224308A patent/JPH07111885B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6467868A (en) | 1989-03-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3246345B2 (en) | Nickel positive electrode for alkaline storage battery and nickel-hydrogen storage battery using the same | |
| US5529857A (en) | Hydrogen-absorbing alloy electrode and process for producing the same | |
| WO2007004703A1 (en) | Nickel-hydrogen battery | |
| JP3104230B2 (en) | Hydrogen storage electrode, method for producing the same, and metal oxide-hydrogen storage battery using the same | |
| JP3245072B2 (en) | Hydrogen storage alloy electrode and method for producing the same | |
| JPH04284354A (en) | Hydrogen storage electrode, its manufacture, and metal-oxide-hydrogen storage battery using the electrode | |
| JPH07111885B2 (en) | Metal oxide-hydrogen storage battery and manufacturing method thereof | |
| JPS6119063A (en) | Hydrogen occlusion electrode | |
| JPS6166366A (en) | Hydrogen storage electrode | |
| JP3567021B2 (en) | Alkaline secondary battery | |
| JPH08264174A (en) | Hydrogen storage alloy cathode and manufacturing method thereof | |
| JP3370071B2 (en) | Hydrogen storage alloy electrode and nickel-metal hydride storage battery using this electrode | |
| JP2989877B2 (en) | Nickel hydride rechargeable battery | |
| JPH0815077B2 (en) | Sealed alkaline storage battery | |
| JPH07107848B2 (en) | Non-sintered positive electrode for alkaline storage battery | |
| JPH0763004B2 (en) | Sealed alkaline storage battery | |
| JPS63266770A (en) | Sealed alkaline storage battery | |
| JPH07111884B2 (en) | Metal oxide / hydrogen storage battery | |
| JP2883450B2 (en) | Hydrogen storage alloy material and method for producing the same | |
| JPS6166372A (en) | Hydrogen-occlusion electrode | |
| JP2558624B2 (en) | Nickel-hydrogen alkaline storage battery | |
| JP3614567B2 (en) | Sealed nickel metal hydride battery | |
| JPH1040950A (en) | Alkaline secondary battery | |
| JP3272226B2 (en) | Hydrogen storage alloy electrode | |
| JP2586752B2 (en) | Hydrogen storage alloy electrode |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |