JPH04284354A - Hydrogen storage electrode, its manufacture, and metal-oxide-hydrogen storage battery using the electrode - Google Patents

Abstract

PURPOSE:To improve the characteristics such as a charge/discharge cycle life, maintenance, and quick charging/discharging of a hydrogen storage alloy electrode. CONSTITUTION:Thermoplastic elastomer 6, hydrophilic resin, and fluororesin 7 are added to hydrogen storage alloy particles 5 to be thermoformed to improve the strength of a hydrogen storage electrode. This constitution can prevent the falling of the hydrogen storage alloy particles due to electrode plate expansion following the charging/discharging of a battery, and can prolong the charge/discharge cycle life of the battery.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a hydrogen storage electrode that electrochemically absorbs and releases hydrogen, mainly consisting of a hydrogen storage alloy and a binder, a method for manufacturing the same, and a metal oxide using the hydrogen storage electrode as a negative electrode. Regarding hydrogen storage batteries.

0002

[Prior Art] Conventionally, hydrogen storage alloys that store and release hydrogen reversibly, hydrogen storage electrodes that use a hydride mixed with a binder, and hydrogen storage electrodes that are used as negative electrodes and nickel oxide as positive electrodes are used. Regarding metal oxide-hydrogen storage batteries,
Many applications have been filed. For example, JP-A-59-60862 discloses a hydrogen storage electrode in which a sheet made by kneading hydrogen storage alloy powder with an alkali-resistant and water-repellent binder and rolling it is pressed against a current collector and integrated. has been done. In addition, a manufacturing method in which a mixture of fluororesin and hydrogen-absorbing alloy powder is formed into a sheet shape and then pressure-bonded to a current collector was developed in JP-A No. 6.
It is disclosed in Japanese Patent No. 2-216163. Such hydrogen storage electrodes can be produced relatively inexpensively, but since they are simply crimped and fixed to an electrode support (current collector), repeated charging and discharging cycles will remove the hydrogen storage electrode from the electrode support. The phenomenon of peeling or falling off of the hydrogen storage alloy powder layer occurs, and as a result, the discharge capacity of the electrode decreases. Furthermore, the internal resistance of the electrode itself increases, making rapid charging and discharging impossible. This phenomenon is particularly noticeable in open-type alkaline storage batteries such as stationary batteries. In order to improve this phenomenon, we used a foamed metal porous material or a fibrous metal porous material as the electrode support (current collector), and created a hydrogen storage electrode in which the electrode support was filled with hydrogen storage alloy powder. Metal oxide-hydrogen storage batteries that use a hydrogen storage electrode as a negative electrode have also been proposed. However, for batteries with relatively large capacity,
As the electrode becomes larger, the bonding force between the hydrogen storage alloy and the electrode support is still weak, and the adhesion is poor, causing the hydrogen storage alloy powder to fall off, which also leads to a decrease in capacity.

0003

[Problem to be solved by the invention] Electrode support (current collector)
A sheet-like hydrogen storage alloy layer made of a mixture of hydrogen storage alloy powder and a binder is pressed onto both sides of the hydrogen storage electrode, or a foamed or fibrous metal porous body is filled with hydrogen storage alloy powder. The storage electrode is employed as a so-called non-sintered electrode. Conventionally, when this type of hydrogen storage electrode is repeatedly charged and discharged, the hydrogen storage alloy becomes finer because it repeatedly expands and contracts during hydrogen storage and hydrogen release. Moreover, since the expansion coefficients of the hydrogen storage alloy powder and the electrode support are different, the adhesion between them is insufficient.
Peeling and cracking of the hydrogen storage alloy powder from the electrode support occurs, and eventually it falls off. Therefore, there are problems in that the discharge capacity of the electrode itself is reduced and the charge/discharge cycle life is shortened due to increased resistance of the electrode.

[0004] When a dispersion of fluororesin (PTFE) is used as a binder, when the fluororesin and hydrogen storage alloy powder are kneaded, the fluororesin becomes fibrous and hardens into a rubbery state, making it difficult to form into a uniform sheet. Become. Moreover, the bonding force between the hydrogen storage alloy particles is weak, so adding a large amount of a binder such as fluororesin to strengthen the bonding strength improves the mechanical strength, but the electrical resistance of the electrode increases and the electrode's electrical resistance increases. Chemical properties are reduced. Therefore, by reducing the amount of binder added and heat-treating at the melting temperature of the fluororesin, the hydrogen storage alloy particles are surrounded by the molten fluororesin, which is the binder. Although the mechanical strength of the electrode itself is improved, the alloy The catalytic action of the surface is reduced, and the rate at which oxygen gas generated from the positive electrode is absorbed and reacted at the negative electrode during overcharging is reduced. Therefore, there is also a problem that the amount of electrolyte decomposed during overcharging increases and the number of times of fluid replacement increases.

In particular, it cannot be used for applications that require little maintenance such as fluid replacement and have a long charge/discharge cycle life, that is, for stacked storage batteries consisting of a relatively large capacity rectangular battery case. This is because multiple electrode substrates are assembled to form a negative electrode group, and over the course of the charge/discharge cycle life, expansion and contraction of the hydrogen-absorbing alloy powder may cause phenomena such as miniaturization, peeling, and falling off, and the electrodes may also be damaged. The problem is to reduce the capacity and shorten the charge/discharge cycle life.

The present invention solves these problems and provides a hydrogen storage electrode that has a long charge/discharge cycle life, requires little maintenance such as fluid replacement, and can be rapidly charged and discharged, and a method for manufacturing the hydrogen storage electrode. metal oxide
The purpose is to provide hydrogen storage batteries.

[0007]

[Means for Solving the Problem] In order to solve this problem, the present invention uses a hydrogen storage alloy alone or together with a solvent such as styrene-butadiene copolymer (SBR), styrene-isoprene copolymer (SIR), styrene-ethylene・Thermoplastic elastomers such as butadiene-styrene copolymer (SEBSR), carboxymethyl cellulose (
Hydrophilic resins such as CMC), methyl cellulose (CM), and polyvinyl alcohol (PVA), fluororesins such as polytetrafluoroethylene (PTFE), polytetrafluoroethylene/hexafluoropropylene (PTFE-PHFP), polyethylene ( PE), silicone resin, etc., and the mixture can be used as an electrode support (current collector), such as a foamed, fibrous metal porous body, a metal net, an expanded metal, or a punched metal. The present invention provides a hydrogen storage electrode in which at least one sheet is filled or coated and integrated, a method for manufacturing the same, and a metal oxide-hydrogen storage battery using the same.

The present invention also provides hydrogen storage alloy powder alone or together with a solvent and two or more types of fluororesins having different melting points, or a thermoplastic elastomer (
Hydrogen in which a mixture containing at least one type of synthetic rubber, at least one type of hydrophilic resin, at least one type of polyethylene resin, and silicone resin is applied or filled onto an electrode support (current collector) and integrated. The present invention provides a storage electrode, a method for manufacturing the same, and a metal oxide-hydrogen storage battery using the same.

[0009]

[Function] In order to extend the life and improve the durability of hydrogen storage electrodes made of hydrogen storage alloys or hydrides, it is necessary to increase the mechanical strength of the hydrogen storage electrodes, avoid increasing the electrical resistance of the electrodes, and avoid overcharging. It is important to prevent discharge (reduction) of the electrolyte. This leads to high reliability and maintenance-free operation. Therefore, in order to increase the mechanical strength of the hydrogen storage electrode, it is important to strengthen the adhesion between the hydrogen storage alloy particles and between the hydrogen storage alloy particles and the electrode support. This is largely due to physical properties such as the shape of the agent. Merely adding a large amount of binder improves the mechanical strength of the electrode, but this is not preferable because it increases the electrical resistance of the electrode itself, leading to a decrease in electrode capacity. Moreover, in metal oxide-hydrogen storage batteries whose rate is determined by the positive electrode, the reaction rate at which the negative electrode absorbs oxygen gas generated from the positive electrode during overcharging decreases, leading to an increase in the pressure inside the battery and a decrease in the amount of electrolyte. Therefore, it is necessary to prevent the hydrogen storage alloy powder from falling off the electrode support (current collector), improve current collection efficiency, and create a hydrogen storage electrode that has a long charge/discharge cycle life and is capable of rapid charging and discharging. For example, it becomes possible to obtain a metal oxide-hydrogen storage battery that requires less maintenance such as replacement fluid.

The effects of the present invention are as follows: First, hydrogen storage alloy powder or hydride-containing powder is used alone or together with a solvent in a mixture containing at least two of thermoplastic elastomers, hydrophilic resins, fluororesins, polyethylene resins, and silicone resins. When this mixture is applied or filled on the electrode support and integrated, the hydrogen storage alloy powder and the binder interact organically due to the physical properties of the mixed binders, and the gas It is possible to manufacture a hydrogen storage electrode that maintains absorption function, mechanical strength, and conductivity. Hydrophilic resins, especially water-soluble synthetic resins, first surround a part of the surface of the hydrogen storage alloy particles with their aqueous solution,
If a fluororesin dispersion is then mixed and made into a paste, the hydrogen storage alloy will reduce the degree of direct contact with the fluororubber and will be less likely to solidify into a rubber-like form, so it can be applied in a uniform sheet to the surface of the electrode support. can be worn. Similarly, foamed or fibrous metal porous bodies can be filled uniformly and efficiently. By static pressing or hot pressing the electrode substrate coated or filled with the paste-like mixture, the bonds between the hydrogen storage alloy particles can be formed using fluororesin particles or molten fluororesin depending on the heat treatment conditions for the fluororesin. This improves the bond between the hydrogen storage alloy particles and the adhesion to the electrode support, making it possible to obtain a durable hydrogen storage electrode. Therefore, it is possible to obtain a long-life metal oxide-hydrogen storage battery in which a hydrogen storage electrode with a long charge-discharge cycle life is used as a negative electrode.

In the above structure, a binder that lowers the conductivity is added to the hydrogen storage electrode, so in order to improve the conductivity of the electrode, a current collector or a metal porous material for reinforcement is placed on the surface of the hydrogen storage electrode substrate. By arranging and further forming a metal thin film or the like, the rapid charge/discharge characteristics can be improved.

[0012] Furthermore, hydrogen storage alloy powder may be used alone or together with a solvent and two or more types of fluororesin having different melting points, or this fluororesin may be combined with at least one type of thermoplastic elastomer (synthetic rubber), hydrophilic resin, polyethylene resin, or silicone resin. The mixture containing the above was added to the electrode support (
A highly viscous resin is used to maintain the bonding force between the hydrogen storage alloy particles, and a highly water-repellent resin is used to exert a catalytic action on the three-phase interface on the surface of the hydrogen storage alloy particles. becomes possible. In particular, in order to strengthen this effect/function, the material is heat treated at the melting temperature of the resin with the lowest melting point among two or more types of fluororesins with different melting points, or a mixture of resins, and then pressure molded. . For example, low melting point fluororesins, other low melting point resins, thermoplastic elastomers (synthetic rubber), etc. are melted through processes such as hot pressing and hot roller pressing, but high melting point resins exist in the form of particles. However, the molten resin strongly bonds between hydrogen-absorbing alloy particles and improves mechanical strength. Fluororesins with high melting points exist in particulate form, so they strengthen the bonds between hydrogen-absorbing alloys and form bonds on the surface of hydrogen-absorbing alloys. acts as a catalyst. Therefore, a metal oxide-hydrogen storage battery using this hydrogen storage electrode as a negative electrode has a long cycle life and requires less maintenance such as fluid replacement.

In order to further improve the catalytic action on the surface of the hydrogen storage alloy and to prevent the hydrogen storage alloy from falling off, a highly water-repellent fluororesin layer is formed on the surface of the hydrogen storage electrode. When forming on the surface, heat treatment is performed at the melting point of the low melting point fluororesin to form a fluororesin layer with strong bonding strength on the surface and prevent the hydrogen storage alloy from falling off. On the other hand, when forming a high melting point fluororesin on the surface, heat treatment is performed at the melting temperature of the low melting point fluororesin, forming a particulate and highly water-repellent layer on the electrode surface, and molten low-resin inside the electrode. The bonding force is strong due to the adhesive force of the fluororesin at the melting point, and the mechanical strength of the electrode itself is improved.

[0014] In this way, by adjusting the heat treatment temperature based on the difference in the melting points of fluororesins or other binders with different melting points, functions such as mechanical strength, electrical conductivity, and catalytic action of the hydrogen storage alloy can be balanced. can be produced well.

Furthermore, since the hydrogen storage alloy contains a binder, the internal resistance of the hydrogen storage electrode increases. To compensate for this, hydrogen storage alloy powder partially coated with conductive metal is used, and two or more types of fluororesin with different melting points are used alone or in combination with other binders as described above to create a low melting point. Heat treatment and pressure molding at the melting temperature of the resin (hot press,
(hot roller press, etc.) to form a hydrogen storage electrode. A metal oxide-hydrogen storage battery using this electrode as a negative electrode has excellent rapid charging and discharging characteristics.

On the other hand, by incorporating a water-repellent binder or a strong binding agent into the inside and surface of the hydrogen storage electrode, retention of the electrolyte may be suppressed. In order to maintain the holding power of the electrolyte within the separator, an organic synthetic resin is melted and fixed on the surface of the separator interposed between the positive and negative electrodes, or it is made of two or more types of fibers including polypropylene and nylon (non-woven fabric). By using mixed fibers, it is possible to suppress the movement of the electrolytic solution within the separator to the outside of the separator, thereby extending the life of the metal oxide-hydrogen storage battery. As the electrolyte held in the separator expands as the charge/discharge cycle progresses, the electrode expands, compressing the separator and causing the electrolyte to move outside the separator, increasing the internal resistance of the battery and reducing battery capacity. Leads to. The present invention has the effect of suppressing this phenomenon.

In addition, if the positive electrode is a non-sintered electrode in which the electrode support (current collector) is coated with a binder and the active material Ni(OH)2, the same binder as the negative electrode is applied. By employing the positive electrode, a metal oxide-hydrogen storage battery can be obtained at a relatively low cost and having strong mechanical strength and durability.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

(Example 1) As the metal constituting the hydrogen storage alloy, an AB5 type multi-component alloy was prepared using a commercially available product with a purity of 99.9% or higher. This hydrogen storage alloy was manufactured by a high frequency induction heating melting method or a plasma arc discharge heating melting method. The composition of the hydrogen storage alloy is, for example, MmNi3.
8Mn0.4Al0.3Co0.5 was selected (Mm is a mixture of rare earth metals). This hydrogen storage alloy was mechanically finely ground using a pulverizer until the average particle size became approximately 30 to 50 μm, thereby obtaining a hydrogen storage alloy powder for a negative electrode. This alloy powder is used as an alkali-resistant organic synthetic resin binder.
Two types of resin were used: a hydrophilic resin and a fluororesin. A 2 wt % aqueous solution of PVA, CMC, MC, etc. was used as the hydrophilic resin, and the amount added was adjusted to 0.5 wt %. Fluororesins include PTFE, PTFE-PHFP (
Using a 10 wt % dispersion of a copolymer, etc., the amount added was adjusted to 2 to 3 wt %.

First, a hydrophilic resin PVA aqueous solution, CMC aqueous solution or MC aqueous solution is added to the hydrogen storage alloy powder and mixed thoroughly.
A dispersion of the HFP copolymer is added and kneaded, and the paste mixture is applied to a certain thickness on the surface of an electrode support (current collector) such as expanded metal, punched metal, or metal net. It is then dried and integrated under pressure. Alternatively, it is filled into a foamed or fibrous metal porous body, dried, and pressurized to a certain thickness to form a hydrogen storage electrode. Figure 1 shows the configuration of this hydrogen storage electrode.
Shown in (a) and (b). FIG. 1(a) shows a structure in which a hydrogen storage alloy powder 2 containing two or more types of binders is applied to the surface of an expanded metal 1 serving as an electrode support. Figure 1 (
B) has a structure in which a foam metal porous body 3 serving as an electrode support is filled with hydrogen storage alloy powder 4 containing two or more types of binders. FIG. 2 shows an enlarged schematic diagram of the bonded state of hydrogen storage alloy particles and two or more types of binders. PVA resin 6 partially covers the surface of the hydrogen storage alloy particles 5, and fine particles of fluororesin (PTFE) 7 serve to bond between the hydrogen storage alloy particles 5 partially through the PVA resin 6. There is. As shown in FIG. 3, this hydrogen storage electrode was used as a negative electrode 8, and a known nickel positive electrode 9, a separator 10, and an alkaline electrolyte 11 were used.
A hydrogen storage battery was constructed. The battery case 12 is equipped with a lid 13 to which a liquid filling stopper 16 which also serves as a safety valve is attached, and furthermore, a negative electrode lead terminal 14 and a positive electrode lead terminal 15 are attached for taking out electric power. A battery constructed with the negative electrode shown in FIG. 1(A) is designated as A, and a battery constructed with the negative electrode shown in FIG. 1(B) is designated B. The size of the negative electrode is 70mm x 100mm x 0.6mmt
So, five of these negative electrode plates were used. The size of the positive electrode is 70mm
A battery was constructed using four of these positive electrode plates with dimensions of 100 mm and 0.8 mm. This battery is rate-limiting with a positive electrode, and has a discharge capacity of 10 Ah. The capacity of the negative electrode was set to about 1.5 times the capacity of the positive electrode. All charge/discharge cycle life tests are 0.5C (current 5A)
It was charged and discharged at 1C (current 10A). The amount of charge was 120% of the battery capacity, and the end-of-discharge voltage was 1.0V.

(Example 2) As an alkali-resistant synthetic resin binder, an SBR solution, SIR solution, SEBSR solution, etc. is used as an example of a toluene solution of a thermoplastic elastomer, and the amount added is about 0.5 to 1 wt%. It was prepared so that After removing the solvent, PTF is used as a fluororesin.
After adding E powder and mixing thoroughly, apply this mixture to the surface of the punched metal (made of nickel or iron-nickel plating) that is the electrode support (current collector), dry it, and pressurize to integrate it. Alternatively, it was filled into a fibrous metal porous body and integrated under pressure to form a hydrogen storage electrode. The structure of this electrode is shown in FIG. As shown in the figure, a mixture 16 of a hydrogen storage alloy and a binder is surrounded and held by metal fibers 15 in a fibrous metal porous body as an electrode support. A schematically enlarged configuration of this state is shown in FIG. The space formed by the metal fibers 15 is filled with hydrogen storage alloy particles 5, and a thin film 17 of SBR, SIR, SEBSR, etc. is partially formed on the surface of the hydrogen storage alloy particles 5. Furthermore, the PTFE powder 18 forms a network with the metal fibers 15, increasing the bonding strength between the hydrogen storage alloys 5 and the metal fibers 15. At the same time, fine water-repellent PTFE powder 18 is interposed on the surface of the hydrogen storage alloy particles 5, forming a so-called three-phase interface, which functions to efficiently absorb oxygen gas generated from the positive electrode during overcharging. ing. The rest is the same hydrogen storage electrode as in Example 1, and a nickel-hydrogen storage battery with this electrode as the negative electrode is
shall be.

(Example 3) Everything was the same as in Example 1 except that the hydrogen storage alloy used in Example 1 was made of a hydrogen storage alloy formed by pressurizing and integrating a current collector or reinforcing metal porous body onto the surface of the hydrogen storage electrode used in Example 1. I made a battery with the same configuration. The electrode configuration is shown in FIGS. 6(a) and 6(b). In FIG. 6(a), for example, hydrogen storage alloy powder 2 is applied to the surface of an electrode support 1 made of expanded metal, and a current collector or reinforcing metal porous body 19 is further disposed on the surface. be. A nickel-hydrogen storage battery using this hydrogen storage electrode as a negative electrode is designated as D. FIG. 6B shows an electrode support 3, for example, a hydrogen storage electrode in which hydrogen storage alloy powder 4 is filled in a foamed metal porous body, and a current collector or reinforcing metal porous body 20 is added to the surface of the hydrogen storage electrode.
is arranged. A nickel-hydrogen storage battery configured with this hydrogen storage electrode as a negative electrode is designated as E.

(Example 4) Example 4 except that the hydrogen storage electrode used in Example 1 with a metal thin film formed on its surface by known means such as electroless plating, electrolytic plating, or vapor deposition was used as the negative electrode. A battery was constructed in the same manner as in Example 1. The configuration of this hydrogen storage electrode is shown in FIG. Hydrogen storage alloy 4
F is a nickel-hydrogen storage battery whose negative electrode is a hydrogen storage electrode in which a metal thin film 21 is formed on the surface of a hydrogen storage electrode filled in a foamed metal porous body 3.

(Example 5) As shown in FIG. 8, the surface of the hydrogen storage electrode with metal thin film used in Example 4 was further coated with PT.
A nickel-hydrogen storage battery is constructed in which the negative electrode is a hydrogen storage electrode on which a water-repellent resin layer 22 mainly composed of FE powder or PTFE-PHFP copolymer powder is formed. The rest is the same as in Example 4. This nickel-metal hydride storage battery is
shall be.

(Example 6) PTFE-PHFP copolymer powder (m.p2
75℃) and PE resin fine powder (m.p 120℃), pressurized and molded, and then the melting temperature of PE resin (120℃)
A nickel-hydrogen storage battery was manufactured using a hydrogen storage electrode as a negative electrode, which was formed by heat treatment for about 10 to 20 minutes or by pressurization and heat treatment again using a hot press, hot roller press, or the like. The rest is the same as in Example 1. This nickel-
Let H and I be hydrogen storage batteries. Hydrogen storage alloy particles 5 constituting this hydrogen storage electrode and PTFE-PHF as a binder
FIG. 9 shows the bonding state between the P copolymer 23 and the PE resin 24. The hydrogen storage alloy particles 5 are bonded via the molten PE resin 24, and the fluororesin 23 is present between the hydrogen storage alloy particles in the form of particles, and the PE resin maintains the mechanical strength of the electrode. The presence of the resin promotes the oxygen gas absorption reaction at the negative electrode.

(Example 7) Two binders with different melting points
types of fluororesins, such as PTFE (m, p327℃)
and PTFE-PHFP copolymer (m.p 275°C) are used alone. Alternatively, in addition to these fluororesins, an aqueous solution of PVA, CMC, MC, etc. is used as a hydrophilic resin. The rest is the same as in Example 1. As the fluororesin, powders or dispersions of PTFE and PTFE-PHFP copolymers having different melting points can be used. At this time,
Heat treatment is performed at a temperature lower than the melting temperature of the fluororesin. After heat treatment, the PTFE-PHFP copolymer, which has a low melting point, becomes molten and has high fluidity, partially surrounding the surface of the hydrogen storage alloy particles and strengthening the bond between the hydrogen storage alloy particles. On the other hand, PTFE resin with a high melting point exists in the form of particles between hydrogen storage alloy particles. This PTFE resin promotes catalytic action on the surface of the hydrogen storage alloy particles. A strong bonding force can be obtained by simply using a static pressure press or a roller press, but the bonding force is even stronger when molding is performed using a hot press or a hot roller press. A nickel-hydrogen storage battery using this hydrogen storage electrode as a negative electrode is designated as J.

On the other hand, if an aqueous solution of PVA, CMC, MC, etc. is applied to the surface of the hydrogen storage alloy particles in advance and a part of the particle surface is coated with a hydrophilic resin such as PVA, CMC, MC, fluorine A homogeneous mixture is created without particles such as resin agglomerating. Furthermore, when a heat treatment step is added, the hydrophilic resin coating layer is partially carbonized, resulting in the effect of improving electrical conductivity. Nickel using this hydrogen storage electrode as a negative electrode
Let K be the hydrogen storage battery.

(Example 8) Low melting point PT, which is two types of fluororesin with different melting points, PE resin and hydrogen storage alloy powder
FE-PHFP copolymer (m.p 275°C) and high melting point PTFE (m.p 327°C) were added, mixed and pressure molded, then PE resin with the lowest melting point (m.p 120°C) was added at the melting temperature. L is a nickel-hydrogen storage battery whose negative electrode is a hydrogen storage electrode integrated by heat treatment, hot pressing, or hot roller pressing. Further, M is a nickel-hydrogen storage battery whose negative electrode is a hydrogen storage electrode that is integrated by heat treatment, hot pressing, or hot roller pressing at the melting temperature of a fluororesin having a low melting point. The rest of the structure was the same as in Example 1. FIGS. 10(a) and 10(b) show the bonding state of the hydrogen storage alloy particles 5 constituting the hydrogen storage electrodes in the batteries L and M with the binder. The fluororesins 23 and 25 shown in FIG. 10(a) exist in the form of particles, and the PE resin 24
melts and strengthens the bonding strength of the hydrogen storage alloy. Figure 10
The PTFE resin 25 shown in (b) exists in the form of particles, and the PTFE resin 25 shown in (b) exists in the form of particles.
FE-PHFP copolymer 23 and PE resin 24 are melted,
Furthermore, the bonding strength of the alloy is increased. The granular PTFE resin 25 serves to help absorb oxygen gas generated from the positive electrode during overcharging.

(Example 9) A nickel-hydrogen storage battery in which a low melting point fluororesin layer is formed on the surface of a hydrogen storage electrode, and the negative electrode is a hydrogen storage electrode formed by heat treatment or pressure molding at the melting point is designated as N. . The rest of the structure was the same as in Examples 7 and 8. In this example, the bonding force of particles on or near the surface of the hydrogen storage electrode is strengthened to prevent the hydrogen storage alloy powder from falling off.

(Example 10) A nickel-based hydrogen storage electrode with a high melting point fluororesin layer formed on the surface of the hydrogen storage electrode, heat treated and pressure molded at the melting temperature of the low melting point fluororesin as a negative electrode. Let O be the hydrogen storage battery. The rest of the structure was the same as in Examples 7 and 8. In this example, the absorption reaction of oxygen gas is promoted on the surface of the hydrogen storage electrode, and the bonding force of the alloy particles inside the electrode is strengthened.

(Example 11) Everything is the same as in Example 7 except that a hydrogen storage alloy powder partially coated with a conductive metal is used. After adding a hydrophilic resin to this alloy powder, two or more types of fluororesins with different melting points are mixed alone or together with a solvent, and filled into a foamed or fibrous metal porous body or formed into a metal net, punched metal, or expanded metal. A hydrogen storage electrode is produced by coating, heat treatment at the melting temperature of the low melting point fluororesin, and then pressure molding, hot pressing, or hot roller pressing. A nickel-hydrogen storage battery using this electrode as a negative electrode is designated as P.

(Example 12) Two or more types of fluororesin and hydrogen storage alloy powder having different melting points were mixed together with a solvent,
After drying, the rubber-like solidified hydrogen storage alloy is crushed and made into granules again, and this hydrogen storage alloy powder is mixed with a hydrophilic resin,
A nickel-hydrogen storage battery is manufactured using a hydrogen storage electrode as a negative electrode, which is coated or filled with an electrode support together with a thermoplastic elastomer, polyethylene resin, and silicone resin, and integrated under pressure or heat treated and integrated under pressure. The rest is the same as in Example 1. Let this nickel-hydrogen storage battery be Q.

(Example 13) A separator is placed between the positive electrode and the negative electrode, and this separator is made of mixed fibers made of two or more materials mainly composed of polypropylene and nylon, and polyethylene resin powder is sprinkled on the surface of the separator. death,
Heat treatment was performed at 120° C. to melt and fix the polyethylene resin on the surface of the separator to form a convex member. A nickel-hydrogen storage battery was manufactured using this separator with convex members. The rest is the same as in Example 1. Let this nickel-hydrogen storage battery be R.

(Example 14) The positive electrode is a non-sintered electrode in which the electrode support (current collector) is coated with a binder and an active material whose main component is Ni(OH)2. and Example 1
A nickel-hydrogen storage battery consisting of a negative electrode was manufactured. The rest is the same as in Example 1. This nickel-hydrogen storage battery is designated as S.

(Example 15) The same as Example 1 except that two or more types of fluororesin powders and carbon powders having different melting points were made into composite particles using a surface modification device. A nickel-hydrogen storage battery using this hydrogen storage electrode as a negative electrode is designated as T.

(Comparative Example 1) PTFE in hydrogen storage alloy powder
Add a dispersion of , mix, and solidify into a rubber-like mixture. Pressure mold the mixture to form a sheet with a thickness of approximately 0.5 mm, and press it onto both sides of an electrode support (expanded metal) to integrate it under pressure. A nickel-hydrogen storage battery was manufactured using the obtained hydrogen storage electrode as a negative electrode. The rest is the same as in Example 1.

(Comparative Example 2) PTFE in hydrogen storage alloy powder
- PHFP copolymer powder is added, mixed, filled into a foam metal porous body serving as an electrode support, pressure molded, and then heat treated near the melting temperature to integrate a nickel hydrogen storage electrode as a negative electrode. Manufactured a hydrogen storage battery. Others are Example 1
is the same as FIG. 11 shows a state in which the molten fluororesin 26 is fixed to the surface of the hydrogen storage alloy particles 5.

Table 1 shows the cycle life test results of nickel-hydrogen storage batteries using the hydrogen storage electrodes as negative electrodes in Examples 1 to 15 and Comparative Examples 1 to 2. The cycle life was defined as a cycle in which the capacity decreased to 80% of the initial discharge capacity, and the test temperature was 25°C. If the electrolyte is discharged due to insufficient oxygen gas absorption reaction at the negative electrode during overcharging, the battery capacity can be restored by replacing the electrolyte as necessary. Therefore, the number of fluid replacements is also used as an evaluation criterion, and the smaller the number of fluid replacements, the better. In other words, if the oxygen gas generated from the positive electrode during overcharging is sufficiently absorbed by the negative electrode, the electrolyte will not decrease and a long charge/discharge cycle will be possible with one replacement fluid.

[0039]

[Table 1]

Table 1 shows the results of measuring the initial discharge capacity, the number of charge/discharge cycles with one fluid replacement, the discharge capacity after 500 cycles, and the rate of decrease in discharge capacity. The initial discharge capacities of A to T of the batteries of the present invention and Comparative Examples 1 and 2, which are conventional batteries, are all discharge capacities of the positive electrode, and are 10 to 10
．． It shows 5Ah. Regarding the number of charge/discharge cycles with one replenishment, batteries whose negative electrode has a high ability to absorb oxygen gas generated from the positive electrode during overcharging have a longer charge/discharge cycle life by approximately 20%. Including batteries using the electrode of the present invention as a negative electrode, the discharge capacity decreases to 8 Ah or less after 220 to 280 charge/discharge cycles. The reason for the decrease in capacity is that the electrolyte decreases and the internal resistance of the battery increases. This is because when this battery is replenished with electrolyte, the discharge capacity is restored again.

As shown in Batteries A, B, D, and E, the electrode support is made of a foamed or fibrous metal porous material rather than one-dimensional structures such as punched metal, expanded metal, or metal net. The one with a three-dimensional structure has better gas absorption ability of the negative electrode. This lengthening of the charge/discharge cycle is partly due to the presence of foamed and fibrous metal skeletons (
This is thought to be because the conductivity of the electrode itself is improved and the surface area is increased by the matrix). Batteries A and B with a binder interposed in the hydrogen storage electrode from a dissolved state
・C, D, E, F, and G prevent the fluororesin particles added later from becoming solidified with the hydrogen storage alloy due to the action of the binder, creating an optimal network between the homogeneous hydrogen storage alloy and the two types of binders. This constitutes a sheet-shaped hydrogen storage electrode substrate. Among these batteries, batteries D, E, F, and G can be charged by forming a current collector, a reinforcing metal porous material, a metal thin film, and a water-repellent fluororesin powder layer on the surface of the electrode substrate. The discharge cycle life has been extended. This is thought to be due to the formation of an optimal three-phase interface on the negative electrode surface and the reduction and catalytic action of oxygen gas.

On the other hand, batteries H, I, J, K, L, M in which a binder in a dissolved state (molten state) is interposed in the hydrogen storage electrode
・N/O improves the mechanical strength of the electrode through the action of the molten binder, and binders with high melting points such as fluororesin (PTFE) remain granular and exist between the hydrogen storage alloys even after heat treatment. It is thought that the hydrogen storage electrode forms an optimal network, forms an optimal three-phase interface on the surface and inside the hydrogen storage electrode, and exhibits oxygen gas reduction and catalytic action.

[0043] In battery P, the surface of the hydrogen storage alloy is coated with a conductive metal to improve the conductivity and corrosion resistance of the hydrogen storage alloy, so it is thought that, in combination with the above effects, an even longer life can be achieved. .

Although Battery Q has the problem of a complicated manufacturing process, it has a relatively large manufacturing process because it has a process of solidifying the hydrogen-absorbing alloy and fluororesin into a rubber-like state and then crushing them into granules again. Since the surface area is maintained and PE resin is added and heat treated, mechanical strength and gas absorption ability are improved. Therefore, it is expected that the battery will have a longer lifespan than conventional batteries.

In contrast, the conventional batteries shown in Comparative Examples 1 and 2 have a charge/discharge cycle life of 100 to 150 cycles. This is thought to be because the negative electrode has a low ability to absorb oxygen gas generated from the positive electrode during overcharging. The battery of Comparative Example 1 is made of hydrogen storage alloy and fluororesin (PTFE).
This is because the mixture (dispersion liquid) solidifies into a rubber-like state, and if it is press-molded into a sheet as it is, the surface area of the electrode itself is small and does not form an optimal network for absorbing oxygen gas.

The battery of Comparative Example 2 was made of fluororesin (PTFE-
Since the mixture of PHFP copolymer and hydrogen storage alloy is heat-treated at melting temperature, the mechanical strength of the electrode itself is improved as shown in Figure 11, but the surface area is reduced, so the gas absorption capacity of the negative electrode is also reduced. It is thought that the electrolyte decreases and the electrolyte decreases significantly during overcharging. This can be understood from the fact that when the weight of the battery was measured after the completion of the charge/discharge cycle, it was lighter than the battery of the present invention.

[0047] The charge/discharge cycle was further continued, and the capacity after 500 cycles was compared. However, after adjusting the electrolyte, the battery capacity was measured so that the characteristics of the hydrogen storage electrodes could be compared.

The battery of the present invention has a discharge capacity of 9.0 to 10
Ah, and its rate of decline remains at 4-14%. Measurements of single electrode potential have confirmed that the rate of this battery is still determined by the positive electrode capacity. Therefore, this decrease in capacity is due to the capacity of the positive electrode, and the influence of the negative electrode has not yet been seen, and further extension of life can be expected by improving the positive electrode. Since Battery S uses a coated non-sintered electrode for the positive electrode, some of the positive electrode active material was observed to fall off and peel from the electrode support, resulting in a decrease in capacity. Among other batteries, those whose capacity decreases by 8 to 10% are considered to have a larger negative electrode capacity than other batteries. It is thought that the component that reduces the capacity of the negative electrode also affects the battery characteristics. However, it is still 2 to 4 times better than conventional batteries. This is largely due to a decrease in the binding strength of the binder and differences in gas absorption capacity and electrode supports. Heat treatment of the binder melts the low-melting point resin, strengthens the bond between the hydrogen storage alloy particles, and reduces the chance of the hydrogen storage alloy falling off or peeling off from the electrode support, resulting in a longer life. In contrast, conventional batteries have a capacity of 6.2 to 8.0 after 500 cycles.
It decreased to 0Ah, and the rate of decrease was as large as 22 to 39%. Therefore, the cycle life is 80% of the capacity retention rate.
Therefore, the lifespan of a conventional battery is less than 500 cycles. As shown in FIG. 11, the reason for this is that the surface area of the alloy is small and the ability of the negative electrode to absorb oxygen gas is also relatively small. Further, in the battery of Comparative Example 1, the internal resistance increased due to peeling between the hydrogen storage alloy sheet and the electrode support, and the capacity decreased due to falling off of the hydrogen storage alloy. In particular, if gas absorption is insufficient during overcharging, this gas will accelerate the phenomenon of alloy falling off.

Although the battery of Comparative Example 2 maintains the mechanical strength of the electrode, as shown in FIG. 11, the surface of the hydrogen storage alloy 5 is surrounded by a large amount of molten resin 26, reducing the hydrogen storage efficiency and reducing the efficiency. A typical network is not configured. Therefore, if only one type of binder is used, it is difficult to strengthen the bonding strength of the hydrogen storage alloy, maintain reactivity with oxygen gas at the negative electrode, efficiently store hydrogen gas, and maintain mechanical strength. Can not. On the other hand, the battery of the present invention forms a hydrogen gas occlusion network, and serves both of the functions of improving the oxygen gas absorption reaction efficiency at the negative electrode and increasing the mechanical strength. Therefore, a battery with a longer charge/discharge cycle and longer life than conventional batteries can be obtained.

Furthermore, in batteries R and T of the present invention,
Better than conventional batteries. First, the electrolyte retention capacity differs depending on the material of the separator. Here, by using a mixed fiber made of a nonwoven fabric of nylon and polypropylene, it has excellent liquid retention and durability, so it is possible to obtain a battery with a relatively long cycle life and little capacity loss. By providing a convex member made of molten synthetic resin on the surface of this separator, the holding power of the electrolyte is further improved.
This suppresses the decrease in capacity.

[0051] Furthermore, the surface of the fluororesin powder can be coated or bonded with a conductive material, such as fine particles of carbon or nickel, using a commonly employed surface modification device (for example, chemical fusion, hybridization, etc.). This makes it possible to provide conductivity while maintaining water repellency, so the internal resistance of the electrode does not decrease and the gas absorption ability of the negative electrode can be maintained to a certain extent, resulting in a long cycle life and a high capacity. A battery with less deterioration can be realized. It is particularly effective when applied to powdered fluororesin having a high melting point. In addition, along with hydrogen storage alloys,
It is also possible to perform surface modification treatment at the same time.

[0052] When the surface of the hydrogen storage alloy is coated with a conductive metal as in Battery P, not only the rapid charging and discharging characteristics are excellent, but also the gas absorption ability at the negative electrode is improved. A toluene solution of thermoplastic elastomer (synthetic rubber) is used as the binder, but if the amount added is less than 0.5 wt%, the binding force is weak and the hydrogen storage electrode lacks durability. On the other hand, 5wt%
If it exceeds this value, the bonding force becomes strong, but the resistance of the hydrogen storage electrode itself increases, causing a decrease in electrode voltage and capacity. Therefore, the amount added is preferably in the range of 0.5 to 5% by weight.

[0053] If the amount of the hydrophilic resin added is less than 0.1 wt%, it becomes difficult to mix the fluororesin homogeneously, making it difficult to form a homogeneous sheet. If it exceeds 5 wt%, the entire surface of the hydrogen storage alloy particles will be surrounded by the resin, which will cause a decrease in electrode capacity, and even if a battery is constructed, the battery life will be shortened and the battery capacity will be small. Therefore, the amount added is 0.
A range of 1 to 5% by weight is desirable.

[0054] If the amount of the fluororesin added is less than 1 wt%, the bonding force will be small and the electrode will lack durability. Furthermore, a three-phase interface is difficult to form on the alloy surface, and oxygen gas absorption does not proceed smoothly. When a battery is constructed, a large amount of electrolyte is discharged, and a large amount of maintenance is required. On the other hand, if it exceeds 10 wt%, the bonding force will become stronger, but the resistance of the hydrogen storage electrode itself will increase, leading to a decrease in battery capacity. Therefore, the amount added is preferably in the range of 1 to 10% by weight.

Although a sintered electrode is used as the positive electrode here, the present invention is not limited to this, and foamed or fiber electrodes may also be used. In addition, organic synthetic resins such as PE, fluororesin, silicone resin, or thermoplastic elastomer were used as the binder, but in short, they are formed from the resin in a dissolved state in water or an organic solvent, or they are formed from a resin in a molten state by heat treatment. Any binder may be used as long as it constitutes a network in which particulate resin (PTFE) is mixed when formed.

Furthermore, although AB5 type multi-component alloy was used as the hydrogen storage alloy, AB2 and AB type multi-component alloys may also be used. Also, approximately 5W of nickel and copper powder were used as conductive materials.
It is effective to add t% to 30wt%.

As described above, two or more types of binders with different melting points are used as binders for hydrogen storage alloys, and heat treatment is performed using the binder with a lower melting point, or binders in a solution state and a particulate state are mixed. Alternatively, by using a conductive metal-coated hydrogen storage alloy, or by forming a current collector, a metal thin film, and a synthetic resin layer on the surface of the hydrogen storage electrode substrate, the inside of the electrode,
By forming a network of synthetic resin and alloy on the surface, we aim to improve the electrode's mechanical strength, gas absorption capacity, and hydrogen storage properties, thereby extending the lifespan and increasing capacity of hydrogen storage electrodes and metal oxide hydrogen storage batteries using them. can be achieved.

[0058]

[Effects of the Invention] As is clear from the above description of the embodiments, according to the present invention, the mechanical strength (durability) of the electrode itself is improved, and the current collecting ability is increased, so that it can be used with large currents. It is possible to realize a hydrogen storage electrode with excellent charge/discharge characteristics, a long charge/discharge cycle life, and easy maintenance, a method for manufacturing the same, and a metal oxide-hydrogen storage battery using the same.

[Brief explanation of the drawing]

[Figure 1] (A) is a desired enlarged sectional view of a hydrogen storage electrode having an electrode support according to an embodiment of the present invention. (B) is an enlarged view of the main part of a hydrogen storage alloy using a porous material as the electrode support. Cross section

[Figure 2] Enlarged cross-sectional view of essential parts showing the bonding state of the hydrogen storage alloy particles and two types of binders

[Figure 3] Cross-sectional view of a nickel-hydrogen storage battery using the same hydrogen storage electrode as the negative electrode

[Figure 4] An enlarged cross-sectional view of the main parts of the hydrogen storage electrode in which the fibrous metal porous body is filled with a hydrogen storage alloy.

[Figure 5] Cross-sectional view showing a fine network of a hydrogen storage electrode filled with a hydrogen storage alloy in the same fibrous metal porous body

[Figure 6
] (A) is a cross-sectional view of a net-type hydrogen storage electrode with a current collector provided on the same surface. (B) is a cross-sectional view of a foam-type hydrogen storage electrode with a current collector provided on the same surface.

[Figure 7] Cross-sectional view of a foamed hydrogen storage electrode with a metal thin film formed on the same surface

[Figure 8] Cross-sectional view of a hydrogen storage electrode with a metal thin film and a fluororesin layer formed on the same surface

[Figure 9] Cross-sectional view showing the bonding state of the hydrogen storage alloy particles, PTFE-PHFP copolymer, and PE resin

[Figure 10] (A) is a cross-sectional view showing a state in which the same hydrogen storage alloy particles and three types of binders are bonded, and only one type of binder is melted. (B) is a cross-sectional view showing the state where the same hydrogen storage alloy particles and three types of bonding Cross-sectional view showing that only one type of binder is in a particle state in the bound state of the agents

[Figure 11] Cross-sectional view showing the bonding state of conventional hydrogen storage alloy particles

[Explanation of symbols]

1 Net type electrode support 2, 4, 16 Hydrogen storage alloy 3 Foamed electrode support 5 Hydrogen storage alloy particles 6 Molten binder 7 Particle binder 8 Negative electrode 9 Positive electrode 10 Separator 15 Metal fiber 17 Molten Synthetic rubber 18 PE fine particles 19, 20 Current collector 21 Metal thin film 22 Water-repellent resin layer 23 PTFE-PHFP copolymer particles 24 Melted PE resin 25 PTFE particles

Claims (27)

[Claims] Claim 1: Hydrogen-absorbing alloy particles alone or together with a solvent, such as thermoplastic elastomer, hydrophilic resin, fluororesin, etc.
A hydrogen storage electrode, which is a mixture of at least two of polyethylene resins or silicone resins, and is integrated by coating or filling an electrode support that also serves as a collector electrode with the mixture as a main component. 2. The thermoplastic elastomer is mainly composed of one or more of styrene-butadiene copolymer, styrene-isoprene copolymer, or styrene-ethylene-butadiene-styrene copolymer, and the amount of the thermoplastic elastomer added is The hydrogen storage electrode according to claim 1, wherein the amount is 0.5 to 5.0% by weight. 3. The hydrophilic resin according to claim 1, wherein the hydrophilic resin is mainly composed of one or more of carboxy methylcellulose, methylcellulose, or polyvinyl alcohol, and the amount of the hydrophilic resin added is 0.1 to 5.0% by weight. hydrogen storage electrode. 4. The fluororesin is mainly composed of one or more of tetrafluoroethylene or a copolymer of tetrafluoroethylene and hexafluoropropylene, and the amount of the fluororesin added is 1 to 1.
The hydrogen storage electrode according to claim 1, wherein the amount is 10% by weight. Claim 5: A claim in which the electrode support that also serves as a current collector is a three-dimensionally structured foamed or fibrous metal porous body, or a single- or two-layer metal net, expanded metal, or punched metal. Item 1. Hydrogen storage electrode according to item 1. 6. The hydrogen storage electrode according to claim 1, wherein a reinforcing metal porous body which also serves as a current collector is integrated with the surface of the hydrogen storage electrode plate under pressure. 7. The hydrogen storage electrode according to claim 1, wherein a thin metal film is further formed on the surface of the hydrogen storage electrode plate by electroless plating, electrolytic plating, metal vapor deposition, or the like. 8. The hydrogen storage electrode according to claim 1, wherein a water-repellent resin layer is further formed on the surface of the hydrogen storage electrode plate. [Claim 9] After mixing a hydrophilic resin with the hydrogen-absorbing alloy powder alone or with a solvent, at least one of fluororesin, thermoplastic elastomer, polyethylene resin, or silicone resin is added in sequence to obtain the lowest melting point. A method for producing a hydrogen storage electrode formed by pressure molding into a sheet at the melting temperature of a resin or below that temperature. [Claim 10] At least one step of applying and fixing water-repellent fluororesin powder to the surface of a hydrogen storage electrode plate and subjecting it to static pressure pressing, roller pressing, hot pressing, or hot roller pressing. The method for manufacturing a hydrogen storage electrode according to claim 9. 11. Hydrogen storage alloy powder alone or together with a solvent containing two or more types of fluororesins having different melting points, or the two types of fluororesins containing one of a thermoplastic elastomer, a hydrophilic resin, a polyethylene resin, and a silicone resin. A hydrogen storage electrode that is integrally constructed by coating or filling an electrode support with a mixture of 12. The hydrogen storage device according to claim 11, wherein two or more types of fluororesin powders having different melting points are applied to the surface of the hydrogen storage electrode to form a layer of low melting point fluororesin on the surface of the hydrogen storage electrode plate. electrode. Claim 13: Claim 11, wherein two or more types of fluororesin powders having different melting points are applied to the surface of the hydrogen storage electrode plate, and a layer of the fluororesin having the highest melting point is formed on the surface of the hydrogen storage electrode plate.
The hydrogen storage electrode described. 14. Hydrogen storage alloy powder alone or together with a solvent and two or more types of fluororesin having different melting points, or this fluororesin and one or more types of thermoplastic elastomer,
In the process of coating or filling an electrode support with a mixture containing at least one type of hydrophilic resin and at least one type of polyethylene resin or silicone resin, two or more types of fluororesin with different melting points or a mixture thereof are used. A method for manufacturing a hydrogen storage electrode, which includes a process of heat treatment at the melting temperature of a low melting point resin among resins and heat molding. [Claim 15] Two or more types of fluororesins having different melting points are used alone, or the fluororesin is combined with at least one type of thermoplastic elastomer (synthetic rubber), one or more types of hydrophilic resin, or at least one of polyethylene resin or silicone resin.
A process of coating and fixing a low melting point fluororesin powder on the surface of a hydrogen storage electrode plate containing hydrogen, heat-treating it at the melting temperature of the low melting point fluororesin, followed by pressure molding, hot pressing or hot roller pressing. at least 1
A method for manufacturing a hydrogen storage electrode having more than one type. [Claim 16] Two or more types of fluororesins having different melting points are used alone, or the fluororesin is combined with a thermoplastic elastomer.
More than 1 type of hydrophilic resin, polyethylene resin,
Alternatively, fluororesin powder with a high melting point is further applied and fixed on the surface of a hydrogen storage electrode plate containing at least one type of silicone resin, heat treated at the melting temperature of the fluororesin with a low melting point, and then pressure molded. Alternatively, a method for producing a hydrogen storage electrode comprising at least one hot pressing or hot roller pressing step. [Claim 17] After adding a hydrophilic resin to the hydrogen storage alloy powder partially coated with a conductive metal, two or more types of fluororesin having different melting points are then mixed alone or together with a solvent to form a foamed or A process of filling it into a fibrous metal porous body, or coating and fixing it on a metal net, punched metal or expanded metal, heat treatment at the melting temperature of the low melting point fluororesin, and then pressure molding, hot pressing or hot roller pressing. A method for manufacturing a hydrogen storage electrode having at least one type. 18. Two or more types of fluororesins and hydrogen storage alloy powders with different melting points are mixed together with a solvent, and after drying, the hydrogen storage alloy solidified into a rubber-like form is crushed and made into granules again. Alloy powder alone or together with at least one type of thermoplastic elastomer, hydrophilic resin, polyethylene resin, or silicone resin is filled into a foamed or fibrous metal porous body, or fixed by coating on the surface of a metal net, punched metal, or expanded metal. and then, a method for producing a hydrogen storage electrode, comprising one or more steps of static pressure pressing, roller pressing, hot pressing, or hot roller pressing. 19. A nickel positive electrode, a negative electrode containing a hydrogen storage alloy or hydride that electrochemically absorbs and releases hydrogen, and an alkaline electrolyte, wherein the negative electrode is a hydrogen absorbing alloy according to any one of claims 1 to 8. Metal oxides mainly used as storage electrodes
Hydrogen storage battery. 20. A nickel positive electrode, a negative electrode containing a hydrogen storage alloy or hydride that electrochemically absorbs and releases hydrogen, and an alkaline electrolyte, wherein the negative electrode is of any one of claims 11 to 1.
3. A metal oxide-hydrogen storage battery mainly comprising the hydrogen storage electrode according to any one of 3. 21. The metal oxide-hydrogen storage battery according to claim 20, wherein the negative electrode is a hydrogen storage electrode heat-treated at the melting temperature of a low melting point resin among two or more types of fluororesins having different melting points. 22. A hydrogen storage device comprising a nickel positive electrode, a negative electrode containing a hydrogen storage alloy or hydride that electrochemically absorbs and releases hydrogen, and an alkaline electrolyte, the negative electrode being partially coated with a conductive metal. A mixture consisting of a storage alloy powder and two or more types of fluororesins having at least different melting points is filled into a foamed or fibrous metal porous body, or coated and fixed on a metal net, punched metal, or expanded metal, and A metal oxide-hydrogen storage battery consisting of a hydrogen storage electrode that is heat treated at the melting temperature of the resin and then pressure molded, hot pressed or hot roller pressed. 23. A nickel positive electrode, a negative electrode containing a hydrogen storage alloy or hydride that electrochemically absorbs and releases hydrogen, and an alkaline electrolyte, a separator is disposed between the positive electrode and the negative electrode, and a surface of the separator is provided. 2. A metal oxide-hydrogen storage battery comprising the hydrogen storage electrode according to claim 1, wherein organic synthetic resin particles are melted and fixed to the hydrogen storage electrode. 24. The metal oxide-hydrogen storage battery according to claim 23, wherein the separator interposed between the positive electrode and the negative electrode is made of a nonwoven fabric of two or more types of fibers including at least polypropylene fibers or nylon fibers. 25. A nickel positive electrode, a negative electrode containing a hydrogen storage alloy or hydride that electrochemically absorbs and releases hydrogen, and an alkaline electrolyte, wherein the positive electrode is made mainly of nickel hydroxide along with a binder on an electrode support. Claims 1 to 4, wherein the negative electrode is a non-sintered electrode coated with an active material.
A metal oxide-hydrogen storage battery mainly comprising the hydrogen storage electrode according to any one of the above. 26. The positive electrode is a non-sintered electrode coated with a mixture of nickel hydroxide as an active material and a binder via an electrode support, and the binder comprises one or more thermoplastic elastomers. , one or more types of hydrophilic resin, one type of fluororesin
The metal oxide-hydrogen storage battery according to claim 25, wherein the metal oxide-hydrogen storage battery is mainly composed of at least two types out of the above types. 27. Oxidation using a hydrogen storage electrode as a negative electrode, in which a mixture of a fluororesin powder, a polyethylene resin powder, and a conductive material is added to a hydrogen storage alloy, and the mixture is coated with or integrated with an electrode support. Metal-hydrogen storage battery.