JP2000149933A - Nickel hydrogen storage battery - Google Patents
Nickel hydrogen storage batteryInfo
- Publication number
- JP2000149933A JP2000149933A JP10324639A JP32463998A JP2000149933A JP 2000149933 A JP2000149933 A JP 2000149933A JP 10324639 A JP10324639 A JP 10324639A JP 32463998 A JP32463998 A JP 32463998A JP 2000149933 A JP2000149933 A JP 2000149933A
- Authority
- JP
- Japan
- Prior art keywords
- hydrogen storage
- hydrogen
- negative electrode
- amount
- 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.)
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Classifications
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- 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
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- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、水酸化ニツケルを
正極活物質とし、水素吸蔵合金を負極活物質としたニツ
ケル水素蓄電池に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nickel hydrogen storage battery using nickel hydroxide as a positive electrode active material and a hydrogen storage alloy as a negative electrode active material.
【０００２】[0002]
【従来の技術】近年、蓄電池を主電源とするポ―タブル
電子機器の小型化に伴い、これらの電子機器は、携帯使
用される機会が増加し、従来よりも広範囲な環境で使用
されるようになつてきた。このため、二次電池について
は、環境の変化、とくに温度変化によらず、安定した性
能を発揮することが要求され、たとえば、ラツプトツプ
型パソコンや携帯電話などに使用する場合、高温および
低温でも常温時と同等の特性が必要とされ、電池に対す
る負荷がますます増大する状況にある。とくに、上記の
ような電子機器に多く利用されているニツケル水素蓄電
池では、さらなる温度特性向上のための検討が続けられ
ている。2. Description of the Related Art In recent years, with the miniaturization of portable electronic devices using a storage battery as a main power source, these electronic devices have been increasingly used in portable environments, and have been used in a wider environment than before. It has become. For this reason, secondary batteries are required to exhibit stable performance irrespective of environmental changes, especially temperature changes.For example, when used in laptop computers and mobile phones, even at high and low temperatures, room temperature A characteristic equivalent to that at the time is required, and the load on the battery is increasing. In particular, with regard to the nickel hydrogen storage battery that is frequently used in the above-described electronic devices, studies for further improving the temperature characteristics are being continued.
【０００３】ところで、ニツケル水素蓄電池では、正極
の利用率を高めて高容量化を達成するため、正極中に金
属コバルト、一酸化コバルト、水酸化コバルトなどのコ
バルト化合物を添加している。これらのコバルト添加剤
は、充電時に正極活物質である水酸化ニツケルの粒子間
を電気的に接続する、Ｃｏ、ＣｏＯ、Ｃｏ（ＯＨ）2→
ＣｏＯＯＨの変化を生じ、コバルトのネツトワ―クを形
成することが知られている。In a nickel hydrogen storage battery, a cobalt compound such as metallic cobalt, cobalt monoxide, and cobalt hydroxide is added to the positive electrode in order to increase the utilization rate of the positive electrode and achieve a high capacity. These cobalt additives are used to electrically connect the particles of nickel hydroxide, which is a positive electrode active material, during charging, to form Co, CoO, Co (OH) 2 →
It is known to cause a change in CoOOH to form a network of cobalt.
【０００４】[0004]
【発明が解決しようとする課題】しかるに、このような
従来構成のニツケル水素蓄電池では、高温環境下に貯蔵
した場合に、電池電圧が著しく低下し、貯蔵前の放電容
量を維持することができないことが明らかとなつた。こ
の問題に対し、高温時に水素吸蔵合金の水素平衡解離圧
を低くする対策も考えられるが、水素平衡解離圧の低下
は、低温での高率放電特性を低下させる結果となり、好
ましくない。However, in such a nickel hydrogen storage battery of the conventional configuration, when stored in a high temperature environment, the battery voltage is significantly reduced, and the discharge capacity before storage cannot be maintained. Became clear. To cope with this problem, a countermeasure for lowering the hydrogen equilibrium dissociation pressure of the hydrogen storage alloy at a high temperature can be considered, but a decrease in the hydrogen equilibrium dissociation pressure results in a decrease in high-rate discharge characteristics at a low temperature, which is not preferable.
【０００５】本発明は、上記従来の事情に照らし、高温
貯蔵特性にすぐれて、高温貯蔵後でも電圧低下が少な
く、高い回復率を有し、しかも低温高率放電特性にもす
ぐれたニツケル水素蓄電池を提供することを目的として
いる。In view of the above-mentioned conventional circumstances, the present invention provides a nickel hydrogen storage battery having excellent high-temperature storage characteristics, a small voltage drop even after high-temperature storage, a high recovery rate, and excellent low-temperature and high-rate discharge characteristics. It is intended to provide.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、上記の目
的を達成するため、鋭意検討した結果、負極活物質とし
て、４５℃での水素吸蔵量０．５重量％時の水素平衡解
離圧が異なり、その比が特定範囲にある少なくとも２種
類の水素吸蔵合金を用いるとともに、上記水素平衡解離
圧の低い水素吸蔵合金の添加量を正極との関係において
特定したときに、高温貯蔵後の電圧低下が少なく、高い
回復率が得られ、しかも低温高率放電特性にもすぐれた
ニツケル水素蓄電池が得られることを見い出し、本発明
を完成するに至つたものである。Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, as a negative electrode active material, hydrogen equilibrium dissociation at 45 ° C. at a hydrogen storage amount of 0.5% by weight. The pressure is different, and at least two kinds of hydrogen storage alloys whose ratios are in a specific range are used, and when the addition amount of the hydrogen storage alloy having a low hydrogen equilibrium dissociation pressure is specified in relation to the positive electrode, after storage at high temperature, The present inventors have found that a nickel hydrogen storage battery with a small voltage drop, a high recovery rate, and excellent low-temperature and high-rate discharge characteristics can be obtained, thereby completing the present invention.
【０００７】本発明は、水酸化ニツケルを活物質とする
正極と水素吸蔵合金よりなる負極とアルカリ水溶液より
なる電解液とセパレ―タを有するニツケル水素蓄電池に
おいて、上記の負極は４５℃での水素吸蔵量０．５重量
％時の水素平衡解離圧が異なる少なくとも２種類の水素
吸蔵合金ａ，ｂを含有し、水素吸蔵合金ｂの上記水素平
衡解離圧が水素吸蔵合金ａの上記水素平衡解離圧の０．
８以下であり、かつ負極中の水素吸蔵合金ｂの添加量が
水素吸蔵量換算で負極に形成される放電リザ―ブの電気
量に対して１〜３倍に相当する量であることを特徴とす
るニツケル水素蓄電池に係るものである。The present invention relates to a nickel hydrogen storage battery having a positive electrode containing nickel hydroxide as an active material, a negative electrode comprising a hydrogen storage alloy, an electrolytic solution comprising an alkaline aqueous solution, and a separator. It contains at least two kinds of hydrogen storage alloys a and b having different hydrogen equilibrium dissociation pressures when the storage amount is 0.5% by weight, and the hydrogen equilibrium dissociation pressure of the hydrogen storage alloy b is the hydrogen equilibrium dissociation pressure of the hydrogen storage alloy a. 0.
8 or less, and the amount of the hydrogen storage alloy b in the negative electrode is equivalent to 1 to 3 times the amount of electricity of the discharge reserve formed in the negative electrode in terms of the hydrogen storage amount. The present invention relates to a nickel hydrogen storage battery.
【０００８】[0008]
【発明の実施の形態】ニツケル水素蓄電池は、負極に正
極を上回る容量を持たせることで、充電末期および放電
末期での負極からのガス発生を抑制している。これは、
正極が満充電または完全に放電されたのちでも、負極に
未充電部分が存在することで、正極から酸素ガスを優先
的に発生させ、負極から水素ガスが発生するのを防止す
るものである。この放電時での負極の過剰容量、つまり
放電リザ―ブの電気量は、充放電反応には直接的には関
与しないが、正極容量を放電末期まで放電させるために
必要で、主に前記した正極中のコバルトネツトワ―クの
形成反応およびその他の副反応（合金腐食など）の対反
応として、負極に形成される。DESCRIPTION OF THE PREFERRED EMBODIMENTS In a nickel hydrogen storage battery, gas generation from the negative electrode at the end of charging and the end of discharging is suppressed by giving the negative electrode a capacity greater than that of the positive electrode. this is,
Even after the positive electrode has been fully charged or completely discharged, the presence of an uncharged portion in the negative electrode allows oxygen gas to be generated preferentially from the positive electrode and prevents hydrogen gas from being generated from the negative electrode. The excess capacity of the negative electrode at the time of this discharge, that is, the amount of electricity in the discharge reserve, is not directly involved in the charge / discharge reaction, but is necessary for discharging the positive electrode capacity until the end of discharge. It is formed on the negative electrode as a counter reaction to the formation reaction of the cobalt network in the positive electrode and other side reactions (such as alloy corrosion).
【０００９】このような構成のニツケル水素蓄電池を高
温で貯蔵した場合、貯蔵中に著しい電圧低下を生じ、貯
蔵後の放電容量も著しく低下する。これは、雰囲気温度
の上昇に伴い、電池内の水素吸蔵合金から発生した水素
ガスが正極中のオキシ水酸化コバルトを還元するためで
ある。ニツケル水素蓄電池では、放電リザ―ブがコバル
トネツトワ―クの形成反応および合金腐食などの副反応
の対反応として負極に形成されるので、負極に吸蔵され
る水素量は、正極中のオキシ水酸化コバルトを２価以下
に還元するのに十分な水素量となつている。つまり、正
極ではオキシ水酸化コバルトの還元で水酸化コバルトお
よび金属コバルトが生じ、その電位が負極電位に接近し
た金属コバルト電位となつて、結果として、電池電圧が
０Ｖ付近となるため、非常に深刻な問題となる。When the nickel hydrogen storage battery having such a configuration is stored at a high temperature, a significant voltage drop occurs during the storage, and the discharge capacity after the storage also decreases significantly. This is because the hydrogen gas generated from the hydrogen storage alloy in the battery reduces cobalt oxyhydroxide in the positive electrode as the ambient temperature increases. In a nickel hydrogen storage battery, the discharge reserve is formed on the negative electrode as a counter reaction to the formation reaction of the cobalt network and the side reaction such as alloy corrosion, so that the amount of hydrogen stored in the negative electrode depends on oxyhydroxide in the positive electrode. The amount of hydrogen is sufficient to reduce cobalt to two or less. In other words, the reduction of cobalt oxyhydroxide at the positive electrode produces cobalt hydroxide and metallic cobalt, and the potential becomes a metallic cobalt potential close to the negative electrode potential. As a result, the battery voltage becomes close to 0 V, which is very serious. Problem.
【００１０】このようなオキシ水酸化コバルトの還元速
度を遅くするために、高温貯蔵時において、放電リザ―
ブとして負極の水素吸蔵合金に吸蔵されている水素ガス
の発生を少なくすることが考えられる。しかし、このよ
うに水素吸蔵合金に吸蔵されている水素量を減少させた
ときには、既述のとおり、低温での高率放電特性を劣化
させるという別の問題を生じる結果となる。[0010] In order to reduce the rate of reduction of such cobalt oxyhydroxide, a discharge reservoir is required during storage at a high temperature.
It is conceivable to reduce the generation of hydrogen gas occluded in the hydrogen storage alloy of the negative electrode. However, when the amount of hydrogen stored in the hydrogen storage alloy is reduced as described above, another problem of deteriorating the high-rate discharge characteristics at low temperatures as described above occurs.
【００１１】本発明者らは、上記問題を克服するため
に、鋭意検討した結果、負極中に４５℃での水素吸蔵量
０．５重量％時の水素平衡解離圧が異なる少なくとも２
種類の水素吸蔵合金ａ，ｂを含有させ、水素吸蔵合金ｂ
としてその上記水素平衡解離圧が水素吸蔵合金ａの上記
水素平衡解離圧の０．８以下となるものを使用し、かつ
この水素吸蔵合金ｂの負極中の添加量を負極に形成され
る放電リザ―ブの電気量に対して１〜３倍となるように
することにより、高温時でのオキシ水酸化コバルトの還
元を抑制でき、しかも低温時での水素の吸蔵放出を円滑
にでき、これにより、高温貯蔵後の電圧低下を抑制でき
るとともに、低温時にすぐれた高率放電特性が得られる
ことを見い出したものである。The present inventors have conducted intensive studies in order to overcome the above-mentioned problems. As a result, at least two hydrogen equilibrium dissociation pressures at 45 ° C. at a hydrogen storage amount of 0.5% by weight differed.
Containing hydrogen storage alloys a and b
The hydrogen equilibrium dissociation pressure is set to 0.8 or less of the hydrogen equilibrium dissociation pressure of the hydrogen storage alloy a, and the amount of the hydrogen storage alloy b added to the negative electrode is determined by the discharge reservoir formed on the negative electrode. -By reducing the amount of electricity to 1 to 3 times the amount of electricity, the reduction of cobalt oxyhydroxide at high temperatures can be suppressed, and the absorption and desorption of hydrogen at low temperatures can be smoothed. It has been found that a voltage drop after high-temperature storage can be suppressed, and excellent high-rate discharge characteristics can be obtained at low temperatures.
【００１２】放電リザ―ブの電気量として負極に存在す
る水素吸蔵合金は、充放電反応に直接的に使用されない
ため、放電リザ―ブとして吸収される水素量だけを水素
平衡解離圧の低い、より安定な水素化物を形成する水素
吸蔵合金ｂに負担させると、高温貯蔵時はこの水素吸蔵
合金ｂが優先的に機能して水素ガスの発生を抑制し、オ
キシ水酸化コバルトの還元を抑制するとともに、電圧低
下速度を遅くできる。しかも、この水素吸蔵合金ｂは、
充放電反応に直接的に関与しないため、低温での高率放
電に影響を及ぼすこともない。このような水素吸蔵合金
ｂは、４５℃での水素吸蔵量０．５重量％時の水素平衡
解離圧が水素吸蔵合金ａの上記水素平衡解離圧の比の
０．８以下、好ましくは０．６以下であるのがよい。
０．８より大きいと、水素吸蔵合金ｂの上記水素平衡解
離圧が水素吸蔵合金ａの上記水素平衡解離圧に近づき、
ガスの発生量が増加し、正極のオキシ水酸化コバルトを
還元することとなる。Since the hydrogen storage alloy present in the negative electrode as the amount of electricity in the discharge reserve is not directly used for the charge / discharge reaction, only the amount of hydrogen absorbed as the discharge reserve is reduced by the hydrogen equilibrium dissociation pressure. When the hydrogen storage alloy b that forms a more stable hydride is charged, the hydrogen storage alloy b functions preferentially during high-temperature storage to suppress the generation of hydrogen gas and the reduction of cobalt oxyhydroxide. At the same time, the voltage reduction speed can be reduced. Moreover, this hydrogen storage alloy b
Since it does not directly participate in the charge / discharge reaction, it does not affect high-rate discharge at low temperatures. In such a hydrogen storage alloy b, the hydrogen equilibrium dissociation pressure at a hydrogen storage amount of 0.5% by weight at 45 ° C. is 0.8 or less, preferably 0.1%, of the ratio of the hydrogen equilibrium dissociation pressure of the hydrogen storage alloy a. It is good to be 6 or less.
When it is larger than 0.8, the hydrogen equilibrium dissociation pressure of the hydrogen storage alloy b approaches the hydrogen equilibrium dissociation pressure of the hydrogen storage alloy a,
The amount of generated gas increases, and the cobalt oxyhydroxide of the positive electrode is reduced.
【００１３】また、水素吸蔵合金ｂの添加量が水素吸蔵
量換算で放電リザ―ブの電気量に対して多すぎると、水
素平衡解離圧の低下を招き、低温での放電特性が劣化す
る。逆に少なすぎると、高温貯蔵時に水素吸蔵合金ａか
らのガス発生が生じ、オキシ水酸化コバルトの還元を促
進し、電圧低下を招くことになる。このため、高温貯蔵
時には水素平衡解離圧の低い水素吸蔵合金ｂが作用して
ガス発生を抑え、低温時には水素平衡解離圧の高い水素
吸蔵合金ａが優先的に作用するように、上記添加量を設
定する必要がある。放電リザ―ブとして負極に吸蔵され
ている水素は、電圧低下を招くオキシ水酸化コバルトの
量を上回つており、しかもその水素は充放電反応に直接
的に関与しないから、低温特性を劣化しない範囲とする
ために、水素吸蔵合金ｂの添加量としては、放電リザ―
ブの電気量を基準として、その１〜３倍、好ましくは
１．５〜２．５倍とするのがよい。On the other hand, if the amount of the hydrogen storage alloy b is too large relative to the amount of electricity in the discharge reserve in terms of the amount of hydrogen storage, the hydrogen equilibrium dissociation pressure is lowered and the discharge characteristics at low temperatures are deteriorated. Conversely, if the amount is too small, gas is generated from the hydrogen storage alloy a during high-temperature storage, which promotes the reduction of cobalt oxyhydroxide and causes a voltage drop. For this reason, the hydrogen storage alloy b having a low hydrogen equilibrium dissociation pressure acts during high-temperature storage to suppress gas generation, and the hydrogen storage alloy a having a high hydrogen equilibrium dissociation pressure acts preferentially at low temperatures, so that the above-mentioned addition amount is increased. Must be set. The amount of hydrogen stored in the negative electrode as a discharge reserve exceeds the amount of cobalt oxyhydroxide causing a voltage drop, and the hydrogen does not directly participate in the charge / discharge reaction, so that the low-temperature characteristics do not deteriorate. In order to maintain the above range, the amount of the hydrogen storage alloy b to be added is determined by the discharge reservoir.
It is good to make it 1 to 3 times, preferably 1.5 to 2.5 times the electric quantity of the electric wire.
【００１４】本発明に用いられる上記の水素吸蔵合金
ａ，ｂは、いずれも、Ｍｍ（Ｌａ、Ｃｅ、Ｎｄ、Ｐｒ）
−Ｎｉ系、Ｔｉ−Ｎｉ、Ｔｉ−ＮｉＺｒ（Ｔｉ2-x Ｚｒ
x Ｖ4- y Ｎｉy ）1-z Ｃｒz 系（ｘ＝０〜１．５、ｙ＝
０．６〜３．５、ｚ＝０．２以下）、Ｔｉ−Ｍｎ系、Ｚ
ｒ−Ｍｎ系などの各種の水素吸蔵合金が挙げられ、これ
らの中から、水素平衡解離圧が本発明の関係を具備する
ものを適宜選択して使用することができる。中でも、水
素平衡解離圧の設計が容易なＭｍ（Ｌａ、Ｃｅ、Ｎｄ、
Ｐｒ）−Ｎｉ系の水素吸蔵合金を用いるのが好ましい。
とくに、本発明では、放電容量を向上するため、水素吸
蔵合金ａとして４５℃での水素吸蔵量０．５重量％時の
水素平衡解離圧が０．１ＭＰａ以下となる水素ガス発生
量が多い合金を用いた場合でも、高温貯蔵時の電圧低下
を抑制することができる。The above-mentioned hydrogen storage alloys a and b used in the present invention are all Mm (La, Ce, Nd, Pr).
-Ni-based, Ti-Ni, Ti-NiZr (Ti 2-x Zr
x V 4- y Ni y) 1 -z Cr z system (x = 0~1.5, y =
0.6-3.5, z = 0.2 or less), Ti-Mn system, Z
Various hydrogen storage alloys such as r-Mn alloys can be mentioned, and from these, those having a hydrogen equilibrium dissociation pressure having the relationship of the present invention can be appropriately selected and used. Among them, Mm (La, Ce, Nd,
It is preferable to use a Pr) -Ni-based hydrogen storage alloy.
In particular, in the present invention, in order to improve the discharge capacity, an alloy having a large amount of hydrogen gas generating a hydrogen equilibrium dissociation pressure of 0.1 MPa or less at a hydrogen storage amount of 0.5% by weight at 45 ° C. is used as the hydrogen storage alloy a. Even when is used, a voltage drop during high-temperature storage can be suppressed.
【００１５】負極は、上記の水素吸蔵合金ａ，ｂとバイ
ンダとを、必要によりニツケル粉末などの導電助剤とと
もにペ―スト化し、これをニツケル発泡体基材などに担
持させ、乾燥後、圧縮成形し、シ―ト状に裁断すること
により、作製される。バインダは水素吸蔵合金を結着で
きる機能を有する限り、とくに制限なく使用できる。具
体的には、ポリエチレン、ポリオレフイン、ポリビニル
アルコ―ル、ポリアクリル酸、ポリテトラフルオロエチ
レン、ポリエチレンオキサイド、ポリビニルピロリド
ン、メチルセルロ―ス、カルボキシメチルセルロ―ス、
ポリＮ−ビニルアセトアミドなどがある。これらの中で
も、ポリエチレンオキサイド、ポリビニルピロリドン、
ポリビニルアルコ―ル、メチルセルロ―ス、カルボキシ
メチルセルロ―ス、ポリＮ−ビニルアセトアミドなどの
水溶性高分子が好ましい。In the negative electrode, the hydrogen storage alloys a and b and the binder are pasted together with a conductive aid such as nickel powder if necessary, and the paste is supported on a nickel foam base material, dried, and then compressed. It is produced by molding and cutting it into sheet form. The binder can be used without any particular limitation as long as it has a function of binding the hydrogen storage alloy. Specifically, polyethylene, polyolefin, polyvinyl alcohol, polyacrylic acid, polytetrafluoroethylene, polyethylene oxide, polyvinylpyrrolidone, methylcellulose, carboxymethylcellulose,
Examples include poly N-vinylacetamide. Among these, polyethylene oxide, polyvinylpyrrolidone,
Water-soluble polymers such as polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose and poly N-vinylacetamide are preferred.
【００１６】正極は、焼結式やペ―スト式のいずれでも
よいが、導電剤であるコバルト化合物の添加が容易で、
かつ量産性にすぐれるペ―スト式が好ましい。このペ―
スト式正極は、水酸化ニツケル粉末とカルボキシメチル
セルロ―ス、ポリテトラフルオロエチレンなどのバイン
ダとを、水や溶剤の存在下で混合してペ―スト化し、こ
れをニツケル発泡体などの導電性多孔基材に担持させ、
乾燥後、圧縮成形し、シ―ト状に裁断することにより、
作製される。その際、上記のペ―スト中に導電剤として
金属コバルトやコバルト酸化物などのコバルト化合物を
含有させることにより、前記したようなオキシ水酸化コ
バルトへの反応およびその他の副反応によつて、負極に
放電リザ―ブが形成される。The positive electrode may be either of a sintered type or a paste type, but it is easy to add a cobalt compound as a conductive agent.
A paste type which is excellent in mass productivity is preferable. This page
The paste-type positive electrode is prepared by mixing nickel hydroxide powder with a binder such as carboxymethyl cellulose or polytetrafluoroethylene in the presence of water or a solvent to form a paste, which is then converted into a conductive material such as a nickel foam. Supported on a porous substrate,
After drying, compression molding, and cutting into sheets,
It is made. At this time, the above-mentioned paste contains a cobalt compound such as metallic cobalt or cobalt oxide as a conductive agent, so that the above-mentioned reaction to cobalt oxyhydroxide and other side reactions cause the negative electrode. , A discharge reserve is formed.
【００１７】正極と負極の容量比は、放電リザ―ブの電
気量を調整するために、負極容量／正極容量が１．３〜
１．８、好ましくは１．４〜１．６の範囲となるように
するのがよい。このような容量比の正負両極と、これら
を分離するナイロン不織布などのセパレ―タを電池缶内
に装填するとともに、電解液として水酸化ナトリウムや
水酸化カリウムなどの水溶液にＬｉＯＨなどの電解質を
溶解させ、また必要により亜鉛や亜鉛化合物さらにはこ
れらとモリブデン、タングステン、クロムまたはこれら
金属の化合物などを添加して調製したアルカリ水溶液を
注入することにより、本発明のニツケル水素蓄電池が得
られる。The capacity ratio between the positive electrode and the negative electrode is adjusted so that the negative electrode capacity / the positive electrode capacity is 1.3 to less in order to adjust the amount of electricity in the discharge reserve.
It is good to be in the range of 1.8, preferably in the range of 1.4 to 1.6. A positive electrode and a negative electrode having such a capacity ratio and a separator such as a nylon nonwoven fabric for separating them are loaded into a battery can, and an electrolyte such as LiOH is dissolved in an aqueous solution such as sodium hydroxide or potassium hydroxide as an electrolyte. The nickel hydrogen storage battery of the present invention can be obtained by injecting, if necessary, zinc or a zinc compound and further adding an alkaline aqueous solution prepared by adding molybdenum, tungsten, chromium or a compound of these metals.
【００１８】[0018]
【実施例】つぎに、本発明の実施例を記載して、より具
体的に説明する。ただし、本発明はこれらの実施例のみ
に限定されるものではない。なお、以下において、部と
あるのは重量部を意味するものとする。Next, an embodiment of the present invention will be described in more detail. However, the present invention is not limited to only these examples. In the following, “parts” means “parts by weight”.
【００１９】実施例１ 水酸化ニツケル粉末１００部に、金属コバルト粉末５
部、２重量％のカルボキシメチルセルロ―ス水溶液（以
下、ＣＭＣ水溶液という）５部、６０重量％のポリテト
ラフルオロエチレン分散液（以下、ＰＴＥＦ分散液とい
う）５部を混合し、ペ―ストとした。このペ―ストをニ
ツケル発泡体基材に充填担持させ、乾燥調圧後、所定寸
法に裁断して、シ―ト状の正極を作製した。EXAMPLE 1 Metal cobalt powder 5 was added to 100 parts of nickel hydroxide powder.
5 parts of a 2% by weight aqueous solution of carboxymethyl cellulose (hereinafter referred to as CMC aqueous solution) and 5 parts of 60% by weight of a polytetrafluoroethylene dispersion (hereinafter referred to as PTEF dispersion) were mixed. did. The paste was filled and supported on a nickel foam base material, and after drying and pressure regulation, it was cut into a predetermined size to produce a sheet-like positive electrode.
【００２０】これとは別に、水素吸蔵合金ａとして４５
℃での水素吸蔵量（水素吸収量）０．５重量％時の水素
平衡解離圧が０．３５ＭＰａであるＭｍＮｉ3.48Ｃｏ
0.74Ｍｎ0.4 Ａｌ0.3 を８５部と、水素吸蔵合金ｂとし
て４５℃での水素吸蔵量０．５重量％時の水素平衡解離
圧が０．０２ＭＰａであるＭｍＮｉ3.9 Ｃｏ0.6 Ｍｎ0.
2 Ａｌ0.35を１５部を混合し、これにニツケル粉末２部
を添加し、さらに２重量％のＣＭＣ水溶液４０部と６０
重量％のＰＴＥＦ分散液２．８部を加えて、ペ―ストと
した。これを穿孔した鉄ニツケルめつき鋼板の両面ニツ
ケルに所定量塗布し、乾燥調圧後、所定寸法に裁断し
て、水素吸蔵電極であるシ―ト状の負極を作製した。Separately, 45 is used as the hydrogen storage alloy a.
MmNi 3.48 Co having a hydrogen equilibrium dissociation pressure of 0.35 MPa when the hydrogen storage amount (hydrogen absorption amount) at 0.5 ° C. is 0.5% by weight.
0.74 Mn 0.4 and Al 0.3 to 85 parts, MmNi 3.9 Co 0.6 Mn 0 hydrogen equilibrium dissociation pressure when the hydrogen storage amount 0.5 wt% at 45 ° C. as a hydrogen storage alloy b is 0.02 MPa.
2 Al 0.35 was mixed with 15 parts, 2 parts of nickel powder were added thereto, and 40 parts of a 2% by weight CMC aqueous solution and 60 parts were added.
2.8 parts by weight of a PTEF dispersion were added to make a paste. A predetermined amount of this was applied to a double-sided nickel of a perforated iron nickel-plated steel plate, dried and pressure-adjusted, and then cut to a predetermined size to produce a sheet-shaped negative electrode serving as a hydrogen storage electrode.
【００２１】上記負極と正極との容量比（負極容量／正
極容量）は１．５となるようにし、水素吸蔵合金ｂの添
加量が負極に形成される放電リザ―ブの電気量の１倍と
なるように設定した。このように作製した正極と負極を
用い、セパレ―タにスルフオン化ポリプロピレンを使用
し、これを介して正負両極を対向するように捲回したも
のを電槽缶に挿入し、３０重量％水酸化カリウム水溶液
を所定量注入後、封口して、密閉式のニツケル水素蓄電
池を得た。The capacity ratio between the negative electrode and the positive electrode (negative electrode capacity / positive electrode capacity) is set to 1.5, and the amount of the hydrogen storage alloy b added is one time the electric quantity of the discharge reserve formed in the negative electrode. It was set to be. Using the positive electrode and the negative electrode prepared as described above, a sulfonated polypropylene was used as a separator, and the positive and negative electrodes were wound so as to face each other, and inserted into a battery case. After injecting a predetermined amount of potassium aqueous solution, it was sealed to obtain a sealed nickel hydrogen storage battery.
【００２２】実施例２ 水素吸蔵合金ａの使用量を５５部に、水素吸蔵合金ｂの
使用量を４５部に変更して、負極と正極との容量比（負
極容量／正極容量）を１．６とし、水素吸蔵合金ｂの添
加量が負極に形成される放電リザ―ブ電気量に対して３
倍となるように設定した以外は、実施例１と同様にし
て、ニツケル水素蓄電池を得た。Example 2 The amount of the hydrogen storage alloy a was changed to 55 parts and the amount of the hydrogen storage alloy b was changed to 45 parts, and the capacity ratio between the negative electrode and the positive electrode (negative electrode capacity / positive electrode capacity) was set to 1. 6, and the amount of the hydrogen storage alloy b added to the amount of discharge reserve formed on the negative electrode is 3
A nickel hydrogen storage battery was obtained in the same manner as in Example 1 except that the setting was made to be twice as large.
【００２３】比較例１ 水素吸蔵合金ｂを使用せず、水素吸蔵合金ａの使用量を
１００部とした以外は、実施例１と同様にして、ニツケ
ル水素蓄電池を得た。Comparative Example 1 A nickel hydrogen storage battery was obtained in the same manner as in Example 1, except that the hydrogen storage alloy b was not used and the amount of the hydrogen storage alloy a was changed to 100 parts.
【００２４】比較例２ 水素吸蔵合金ａを使用せず、水素吸蔵合金ｂの使用量を
１００部とした以外は、実施例１と同様にして、ニツケ
ル水素蓄電池を得た。Comparative Example 2 A nickel hydrogen storage battery was obtained in the same manner as in Example 1 except that the hydrogen storage alloy a was not used and the amount of the hydrogen storage alloy b was changed to 100 parts.
【００２５】上記の実施例１，２および比較例１，２で
得た各ニツケル水素蓄電池の性能を調べるために、各電
池を６０℃で１７時間保持し、２５℃，０．２ＣＡで７
時間の充電と０．２ＣＡの放電（終止電圧１．０Ｖ）を
５サイクル繰り返したのち、下記の方法により、高温貯
蔵特性および低温高率放電特性を調べた。これらの結果
は、表１に示されるとおりであつた。In order to examine the performance of each of the nickel hydrogen storage batteries obtained in Examples 1 and 2 and Comparative Examples 1 and 2, each battery was kept at 60 ° C. for 17 hours, and at 25 ° C. and 0.2 CA for 7 hours.
After repeating charging for 5 hours and discharging at 0.2 CA (final voltage: 1.0 V) for 5 cycles, high-temperature storage characteristics and low-temperature high-rate discharge characteristics were examined by the following methods. These results were as shown in Table 1.
【００２６】＜高温貯蔵特性＞２５℃，０．２５ＣＡで
６時間充電後、１時間休止し、０．２ＣＡで電池電圧が
１．０Ｖになるまで放電を行つたときの放電容量を測定
し、これを初期の電池容量とした。つぎに、この電池容
量測定後の放電状態にある電池を８０℃で１０日間貯蔵
したのちの電圧値を測定し、貯蔵前の電圧値との差を求
め、低下電圧値とした。また、試験後の電池を２５℃に
冷却し、上記初期の電池容量の測定の場合と同様にし
て、貯蔵後の電池容量を測定し、初期の電池容量に対す
る回復率を求めた。<High Temperature Storage Characteristics> After charging at 25 ° C. and 0.25 CA for 6 hours, the battery was suspended for 1 hour, and the discharge capacity was measured when the battery was discharged at 0.2 CA until the battery voltage reached 1.0 V. This was taken as the initial battery capacity. Next, the battery in the discharged state after the measurement of the battery capacity was stored at 80 ° C. for 10 days, the voltage value was measured, and the difference from the voltage value before the storage was obtained, which was defined as the reduced voltage value. Further, the battery after the test was cooled to 25 ° C., and the battery capacity after storage was measured in the same manner as in the measurement of the initial battery capacity, and the recovery rate with respect to the initial battery capacity was obtained.
【００２７】＜低温高率放電特性＞２５℃，０．２５Ｃ
Ａで６時間充電後、─２０℃の恒温槽中で５時間保持
し、１．０ＣＡで電池電圧が１．０Ｖになるまで放電を
行つたときの低温高率放電容量を測定した。この低温高
率放電容量の前記初期の電池容量に対する割合（％）を
求めて、これを低温高率放電特性として評価した。<Low temperature high rate discharge characteristics> 25 ° C, 0.25C
After charging for 6 hours at A, the battery was kept in a thermostat at ─20 ° C. for 5 hours, and the low-temperature high-rate discharge capacity was measured when the battery was discharged at 1.0 CA until the battery voltage became 1.0 V. The ratio (%) of the low-temperature high-rate discharge capacity to the initial battery capacity was determined and evaluated as low-temperature high-rate discharge characteristics.
【００２８】 [0028]
【００２９】上記表１の結果から明らかなように、実施
例１〜２のニツケル水素蓄電池は、高温貯蔵後でも電圧
低下が小さく、高い回復率が得られているとともに、低
温高率放電での容量が大きいことがわかる。これに対し
て、比較例１，２のニツケル水素蓄電池では、高温貯蔵
特性に劣つているか、あるいは低温高率放電特性に劣つ
ており、両特性をともに満足させることができない。As is clear from the results shown in Table 1, the nickel hydrogen storage batteries of Examples 1 and 2 exhibited a small voltage drop even after high-temperature storage, a high recovery rate, and a low-temperature high-rate discharge. It can be seen that the capacity is large. On the other hand, the nickel hydrogen storage batteries of Comparative Examples 1 and 2 are inferior in high-temperature storage characteristics or inferior in low-temperature high-rate discharge characteristics, and cannot satisfy both characteristics.
【００３０】[0030]
【発明の効果】以上のように、本発明は、負極中に４５
℃での水素吸蔵量０．５重量％時の水素平衡解離圧が異
なる少なくとも２種類の水素吸蔵合金ａ，ｂを含有し、
一方の水素吸蔵合金ｂとして、その上記水素平衡解離圧
が水素吸蔵合金ａの上記水素平衡解離圧の０．８以下で
あるものを使用し、さらに負極中の水素吸蔵合金ｂの添
加量を水素吸蔵量換算で負極に形成される放電リザ―ブ
の電気量に対して１〜３倍に相当する量とすることによ
り、高温貯蔵後にも電圧低下が少なく、高い回復率を有
し、しかも低温高率放電特性にすぐれたニツケル水素蓄
電池を提供することができる。As described above, according to the present invention, 45
At least two kinds of hydrogen storage alloys a and b having different hydrogen equilibrium dissociation pressures when the hydrogen storage amount at 0.5 ° C. is 0.5% by weight,
As the hydrogen storage alloy b, one having a hydrogen equilibrium dissociation pressure of 0.8 or less of the hydrogen equilibrium dissociation pressure of the hydrogen storage alloy a is used. By making the amount equivalent to 1 to 3 times the amount of electricity of the discharge reserve formed on the negative electrode in terms of occlusion amount, voltage drop is small even after storage at high temperature, high recovery rate, and low temperature A nickel hydrogen storage battery having excellent high-rate discharge characteristics can be provided.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 磯貝 正人 大阪府茨木市丑寅一丁目１番88号 日立マ クセル株式会社内 (72)発明者 長井 龍 大阪府茨木市丑寅一丁目１番88号 日立マ クセル株式会社内 Ｆターム(参考） 5H028 AA01 AA05 CC10 EE01 HH01 HH08 HH09 HH10 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masato Isogai 1-1-88 Ushitora, Ibaraki-shi, Osaka Inside Hitachi Maxell Co., Ltd. (72) Inventor Ryu Nagai 1-188 Ushitora, Ibaraki-shi, Osaka Hitachi Maxell F term (reference) 5H028 AA01 AA05 CC10 EE01 HH01 HH08 HH09 HH10
Claims (1)
素吸蔵合金よりなる負極とアルカリ水溶液よりなる電解
液とセパレ―タを有するニツケル水素蓄電池において、
上記の負極は４５℃での水素吸蔵量０．５重量％時の水
素平衡解離圧が異なる少なくとも２種類の水素吸蔵合金
ａ，ｂを含有し、水素吸蔵合金ｂの上記水素平衡解離圧
が水素吸蔵合金ａの上記水素平衡解離圧の０．８以下で
あり、かつ負極中の水素吸蔵合金ｂの添加量が水素吸蔵
量換算で負極に形成される放電リザ―ブの電気量に対し
て１〜３倍に相当する量であることを特徴とするニツケ
ル水素蓄電池。1. A nickel hydrogen storage battery comprising a positive electrode containing nickel hydroxide as an active material, a negative electrode comprising a hydrogen storage alloy, an electrolytic solution comprising an alkaline aqueous solution, and a separator.
The negative electrode contains at least two types of hydrogen storage alloys a and b having different hydrogen equilibrium dissociation pressures at 45 ° C. when the hydrogen storage amount is 0.5% by weight, and the hydrogen equilibrium dissociation pressure of the hydrogen storage alloy b is hydrogen. The hydrogen equilibrium dissociation pressure of the storage alloy a is 0.8 or less, and the addition amount of the hydrogen storage alloy b in the negative electrode is 1 to the electric quantity of the discharge reserve formed in the negative electrode in terms of the hydrogen storage amount. A nickel hydrogen storage battery having an amount corresponding to about three times.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10324639A JP2000149933A (en) | 1998-11-16 | 1998-11-16 | Nickel hydrogen storage battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10324639A JP2000149933A (en) | 1998-11-16 | 1998-11-16 | Nickel hydrogen storage battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000149933A true JP2000149933A (en) | 2000-05-30 |
Family
ID=18168084
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10324639A Withdrawn JP2000149933A (en) | 1998-11-16 | 1998-11-16 | Nickel hydrogen storage battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000149933A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001291511A (en) * | 2000-04-07 | 2001-10-19 | Toshiba Corp | Hydrogen storage alloy electrode, secondary battery, hybrid car and electric vehicle |
| JP2001307720A (en) * | 2000-04-21 | 2001-11-02 | Toshiba Corp | Hydrogen storage alloy electrode, secondary battery, hybrid car, and electric vehicle |
| CN103337609A (en) * | 2013-05-11 | 2013-10-02 | 深圳市电科电源股份有限公司 | Method for manufacturing ultra-high temperature overcharging-resistance long service life nickel-hydrogen battery |
| CN106025391A (en) * | 2015-03-27 | 2016-10-12 | 朴力美电动车辆活力株式会社 | Nickel-metal hydride battery |
| US20180090754A1 (en) * | 2016-09-26 | 2018-03-29 | Primearth Ev Energy Co., Ltd. | Nickel-metal hydride battery |
| JP2018056113A (en) * | 2016-09-26 | 2018-04-05 | プライムアースＥｖエナジー株式会社 | Nickel hydrogen storage battery |
-
1998
- 1998-11-16 JP JP10324639A patent/JP2000149933A/en not_active Withdrawn
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001291511A (en) * | 2000-04-07 | 2001-10-19 | Toshiba Corp | Hydrogen storage alloy electrode, secondary battery, hybrid car and electric vehicle |
| JP2001307720A (en) * | 2000-04-21 | 2001-11-02 | Toshiba Corp | Hydrogen storage alloy electrode, secondary battery, hybrid car, and electric vehicle |
| CN103337609A (en) * | 2013-05-11 | 2013-10-02 | 深圳市电科电源股份有限公司 | Method for manufacturing ultra-high temperature overcharging-resistance long service life nickel-hydrogen battery |
| CN106025391A (en) * | 2015-03-27 | 2016-10-12 | 朴力美电动车辆活力株式会社 | Nickel-metal hydride battery |
| JP2016186844A (en) * | 2015-03-27 | 2016-10-27 | プライムアースＥｖエナジー株式会社 | Nickel-hydrogen storage cell |
| US20180090754A1 (en) * | 2016-09-26 | 2018-03-29 | Primearth Ev Energy Co., Ltd. | Nickel-metal hydride battery |
| CN107871902A (en) * | 2016-09-26 | 2018-04-03 | 朴力美电动车辆活力株式会社 | Nickel-hydrogen accumulator |
| JP2018056113A (en) * | 2016-09-26 | 2018-04-05 | プライムアースＥｖエナジー株式会社 | Nickel hydrogen storage battery |
| CN107871902B (en) * | 2016-09-26 | 2020-05-08 | 朴力美电动车辆活力株式会社 | Nickel-hydrogen storage battery |
| US10658660B2 (en) * | 2016-09-26 | 2020-05-19 | Primearth Ev Energy Co., Ltd. | Nickel-metal hydride battery |
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