JP2002198055A - Paste-like thin electrode for battery, its manufacturing method and secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode of light weight and low cost and its manufacturing method, equivalent to an electrode of which sustainability and collectivity of powder of active substance or the like is sintered type or 3DM type, and further, to provide a light-weight secondary battery using the electrode. SOLUTION: A three-dimensional electrode base body 9 is made with a nickel foil by mechanically processing its rugged part, to which active material 10 is filled and, after that, the rugged part is pressurized so that it is slanted to one direction, to make up an electrode 1, using which, the secondary battery is structured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste type thin electrode for a secondary battery, which has a low cost, a high rate discharge characteristic and an improved cycle life, and a secondary battery using the same.

[0002]

2. Description of the Related Art At present, electrode types mainly industrialized as battery electrodes, particularly secondary battery electrodes, are roughly classified into two-dimensional core materials in which metal powder is sintered on both sides thereof. A sintered electrode in which a porous three-dimensional electrode substrate is filled with an active material and the like, and powders of the active material and the like in various two-dimensional core materials or metal bags or cylinders without using a sintered substrate. It is classified into a non-sintered electrode which is integrated by coating or filling.

[0003] Generally, the former is excellent in electron conductivity (high-rate charge / discharge characteristics) and excellent in mechanical strength and active material retention because of the large amount of metal used for the sintered substrate. On the other hand, the energy density is small because the filling amount of the active material in the electrode substrate is small because the volume of the electrode substrate is large,
It also has the disadvantage of heavy electrodes.

On the other hand, typical non-sintered electrodes are:
The active material powder or the like is simply applied or directly impregnated onto the electrode substrate on a core material that is inexpensive and easy to manufacture, so it is inexpensive, has a large energy density of the electrode, and is lightweight. In addition, it has a problem in that it is inferior in ability and inferior in mechanical strength and retention of active materials.

[0005] These problems are serious problems in a secondary battery that repeatedly charges and discharges many times, and various measures are taken depending on the battery system. Therefore, there are many non-sintering methods that have been devised to improve these problems.
Paste or coating, which is a method of applying pastes or slurries obtained by kneading active material powders with a conductive material or a binder and a solution to a two-dimensional core material of various shapes, Alternatively, it is represented by a pocket type or a clad type in which an active material powder or the like is packed in a metal bag or cylinder provided with an infinite number of pores provided for an electrochemical reaction.

Examples of the former non-sintered type electrode include a cadmium negative electrode of an alkaline storage battery, a metal hydride negative electrode, a positive and negative electrode of a lithium ion battery, and a positive and negative electrode of a lead battery. The latter type of non-sintered electrode is used, for example, in a part of a nickel positive electrode of an alkaline storage battery or in some lead batteries. As the core material of the electrode described here, a punching metal, a metal screen, an expanded metal, a metal grid, and the like are properly used depending on a battery system and purpose.

[0007] However, recently, as a new type of non-sintering type, USP 4,251,
An electrode (hereinafter referred to as 3D) for filling a paste such as an active material powder into a foamed nickel porous substrate or nickel fiber substrate having a three-dimensional spread proposed in US Pat.
M). However, this type of electrode has high capacity and high reliability, and the amount of metal per volume used for the substrate is small. There is a technical problem that the strength is weak and the electron conductivity of the entire electrode is inferior due to a large pore size in the electrode substrate, and further, there is a problem that the cost of the electrode substrate is high.

Here, the present invention relates to the above-mentioned 3DM method, and particularly to the improvement of a three-dimensional electrode base of an electrode used in an alkaline secondary battery at present. The nickel positive electrode for an alkaline storage battery, in which almost all of the above electrode systems are properly used depending on the application, will be described taking a small cylindrical sealed nickel-metal hydride storage battery as an application example thereof.

[0009] The nickel positive electrode for alkaline storage batteries is a sintered electrode developed in Germany during the Second World War and has high performance and robustness.
That is, a sintered electrode has begun to be used in a square Ni / Cd battery, which is required to have high performance and high reliability, instead of a pocket electrode or the like. A similar change to the sintering method occurred in the negative electrode. Cylindrical sealed Ni / Cd developed
Sintering type positive / negative electrodes have become the mainstream of battery electrodes, because they can be easily processed into thin electrodes.
Small cylindrical sealed batteries typified by this NiCd battery (Ni / Cd battery) have shown tremendous growth as power supplies for portable small electronic devices such as camcorders and CDs, which have grown remarkably in Japan since the early 1980s. I did it. But,
Since the 1990s, new nickel-metal hydride batteries (Ni / MH batteries) and lithium-ion batteries have been put into practical use one after another, and have begun to enter the two-cell battery market. Looking at new markets, recently, power tools for power tools such as electric tools, power supplies for transportation, that is, electric vehicles (E
V), hybrid vehicles (HEV), electrically assisted bicycles, and other applications have begun to grow, and Ni / MH batteries have mainly been used as power sources for these applications. The above-mentioned Ni / Cd battery and the recently growing Ni / MH
A nickel positive electrode is used for the positive electrode of the battery.
At present, both types of the M type are used for different purposes.

[0010] In the structure of the mass-produced nickel positive electrode, the non-sintered electrode is limited to the pocket electrode due to mechanical stability, and the structure is such that the active material powder is hard to fall off as described above. It has a structure in which active material powder and the like are packed in a liquid-resistant metal bag provided with countless micropores. On the other hand, in the sintered electrode, the nickel fine powder is sintered at a high temperature together with the core material to impregnate the space of the sintered base in a state where the nickel granules are connected with the salt solution of the active material. A structure in which the active material is filled in the space inside the electrode substrate by the step of converting into the active material is adopted. Naturally, the active material in this case is not in a powder form.

In 1981, another non-sintered 3DM type different from the pocket type was used in the 1981 ECS Fal
l Meeting (Detroit) Abstract No.10 reported as a nickel positive electrode using foamed nickel. This electrode has a structure in which a foamed nickel porous body having a high porosity and a large pore diameter is used as a base, and an active material powder or the like is filled therein.

By using this foamed nickel for the base, a high-capacity and lightweight nickel positive electrode has been realized.
For high-rate discharge applications, even if the inner spherical space has a small diameter, it is as large as about 450 μm, so that the overall active material is inferior in reactivity and expensive. Therefore, batteries using a sintered nickel positive electrode having excellent high-rate discharge characteristics are still mainstream for applications requiring high power.

However, even in applications requiring high power, self-discharge occurs due to the disadvantages of the sintered electrode, the low energy density and heavy weight, and the incorporation of nitrate ions during the manufacturing process, which does not occur in the non-sintered electrode. Is becoming a practical problem in accordance with the spread of applications, and it is desired to introduce a paste type (or a coating type) electrode. Since high-rate discharge is required in this application, generally, a thin electrode having an increased facing area is used as an electrode, but the area of use of a core material or a base in the electrode increases. Therefore, a low-cost two-dimensional core material and a three-dimensional base are particularly required. In addition, as a high-power application and the like, they are used in a hybrid vehicle (HEV) or the like, and are prerequisites to be lightweight.

Therefore, as a new construction method to replace expensive foamed nickel such as 3DM type, which is a kind of paste type, or as a three-dimensional core material or electrode base, (1) punching metal or expanded metal or the like; A plurality of extremely thin electrodes obtained by applying active material powder or the like to the core material are stacked to form one electrode. (2) A myriad of hair-like or elongated needle-like metals are attached to a perforated core material such as punching metal or metal foil. (USP
(5,840,444) (3) A large number of burrs are provided on the metal plate in the thickness direction of the plate surface. (USP 5,543,250) (4) The metal plate is processed into a corrugated shape to make it three-dimensional. If necessary, holes with burrs are provided at the tips of the corrugations to supplement the three-dimensional structure. (USP 5,824,435) and the like have been proposed.

However, not all of the problems have been solved by the above-described constitutional methods (1) to (4) or the electrode substrate. In (1), there remains a problem that the integrated thin electrodes cannot be basically prevented from being separated from each other due to expansion and contraction of the active material due to charge and discharge. In (2), the thickness of the filled paste is not uniform because the bonding strength between the hairy or elongated needle-like metal fibers and the base metal plate is insufficient and the core material itself does not have uniform holes. In addition to the characteristic problems such as the above, there is a problem that the cost is higher than that of the conventional substrate. In (3), three-dimensionalization of the electrode base is basically insufficient.
There is a problem in retention and charge / discharge characteristics of the active material powder or the like against falling off. In (4), these problems are considerably improved, and low cost can be expected. However, if a roll pressing process used in normal mass production is adopted, the electrode is stretched in the waveform direction by the roll pressing. Problems remain in that it is difficult to maintain a desired three-dimensional shape of the electrode substrate, and that the active material is easily peeled from the electrode substrate when being wound around a spiral electrode or during repeated charge and discharge.

Further, in the application of a new alkaline storage battery in the market, a power supply for a power tool such as an electric tool requires a high rate discharge characteristic due to a method of using the power tool. Car (H
Power supplies for mobile objects such as EVs and electric assist bicycles are reduced in size and weight, that is, reduced in volume, in order to improve the high-rate discharge characteristics and secure the space inside the vehicle and improve fuel efficiency, which are the applications. Improvements in energy density (Wh / l) and weight energy density (Wh / kg) are particularly desired.

[0017]

SUMMARY OF THE INVENTION The present invention is intended to improve the high-rate discharge characteristics, which is an object of the present invention, in an electrode. In addition, the present invention provides an electrode having a current collection property equivalent to that of a sintered type electrode and a 3DM type electrode, having an excellent cycle life, and being lightweight and inexpensive, and a method for producing the same. An object is to provide a secondary battery.

[0018]

Means for Solving the Problems The present inventor has determined that, in an electrode of an alkaline storage battery or the like, (a) a substrate having a hollow and innumerable irregularities is used as a conductive electrode substrate; The electrode base is made to have a thickness substantially equal to the electrode thickness, and (c) a part or the whole of the conductive electrode base is suppressed from being made two-dimensional by a roll pressing operation after filling the paste such as an active material. In addition, in order to maintain the current collecting ability of the entire electrode, the irregularities of the conductive electrode substrate are almost alternately arranged, and (d) active by repeating the spiral winding operation of the electrode and subsequent charge / discharge. In order to suppress the exfoliation of the material powder and the like from the conductive electrode substrate and enhance the retention of the active material powder and the like, the wall of the hollow uneven portion is distorted in the electrode thickness direction, and the uneven portion is particularly close to the tip. In a shape inclined in the direction It is obtained by solving the above problems. Further, even with the active material powder particles farthest from the conductive electrode substrate, the shortest distance to the conductive electrode substrate is 150 μm.
By holding within, charge and discharge reaction of the active material powder,
In particular, the high-rate discharge reaction can be further enhanced, and the ratio (t ₂ / t ₁ ) of the bottom thickness (t ₂ ) to the side wall thickness (t ₁ ) of the cylindrical battery case is 1. By using a battery case of 5 or more, that is, a case in which the side wall surface is thinned, the secondary battery is further reduced in weight and capacity.

The present invention is not particularly limited to a nickel positive electrode. However, when the present invention is used for a nickel positive electrode for an alkaline storage battery, and particularly for a thin nickel positive electrode having an electrode thickness of 500 μm or less, sintering and plating can be performed. Without applying, an electrode using an inexpensive, lightweight conductive electrode substrate that can be processed only by mechanical operation is obtained, and has excellent charge / discharge characteristics and excellent retention of active material powder, etc. It is possible to obtain an inexpensive and lightweight nickel-metal hydride storage battery (Ni / MH battery) having a closed cylindrical shape and a rectangular shape which is excellent in high-rate discharge characteristics and has a long life.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to the drawings, a nickel positive electrode 1 having a thickness of 500 μm or less, mainly composed of nickel hydroxide powder, and a hydrogen storage alloy powder as a main material. An electrode group obtained by winding an alloy negative electrode 2 having a much thinner electrode thickness through a separator 3 made of a nonwoven fabric of a polyolefin-based synthetic resin fiber is inserted into a cylindrical metal case, and then an alkaline electrolyte Will be described as an example of a cylindrical sealed nickel-metal hydride storage battery in which is sealed after injection.

Here, the positive electrode is made of a nickel foil having a thickness of 20 to 50 μm, and the upper and lower molds are provided with innumerable irregularities substantially alternately, and are pressed between the molds which can be engaged to form a three-dimensional structure. A paste 10 obtained by kneading the main material was filled in the conductive electrode substrate 9 thus obtained, and an electrode obtained by pressing after drying was adopted. The thickness of the conductive electrode substrate is 20μ.
When it is approximately equal to m, the conductive electrode substrate can be obtained by an electrolytic metal deposition method because of its low cost and ease of manufacture. For example, pH mainly containing nickel sulfate
In a normal electrolytic cell holding an aqueous solution of 2.0, a thickness of 20 μm with countless irregularities on the surface of the cathode was provided.
m can be obtained by electrolytic deposition, and this nickel substrate can also be obtained as a long continuous foil having countless irregularities on the surface by using a rotary drum having irregularities on the surface of the cathode. . Usually, the nickel substrate is usually obtained as an electrode substrate after annealing at about 850 ° C. in order to obtain mechanical strength.

The three-dimensional structure of the conductive electrode substrate, which is three-dimensionally formed to substantially the thickness of the electrode, has a structure in which it is bent strongly in one direction as it reaches the tip of the hollow concavo-convex portion, and wraps the space. By virtue of this, it is possible to obtain a long-life electrode with excellent current collecting properties and a retention property of powders such as an active material, which is not inferior to that of a sintering type or a 3DM type. . In addition, since the above-mentioned conductive electrode substrate having a three-dimensional structure can be manufactured simply by passing between the molds that engage in an uneven shape, it is easy to manufacture, so it is inexpensive, and the electrode breaks even when the electrode is spirally wound. There was nothing. As a result, a Ni / MH battery that is easy to process, has high performance, is inexpensive and has high reliability is obtained.

The alloy anode has improved current collecting performance because it is about half the thickness of the cathode, and thus withstands a certain high-rate discharge.
When a higher discharge rate is required, it is preferable to use the three-dimensional nickel electrode substrate of the present invention also for the alloy negative electrode serving as the conductive electrode substrate.

Although the Ni / MH battery is described here for convenience of explanation as described above, the Ni / MH battery requires a high-rate discharge. The present application can be similarly applied.

FIG. 1 is a cross-sectional view of the nickel positive electrode 1 of the present invention taken along line AA in FIG. In the figure, reference numeral 9 denotes a nickel metal part constituting a three-dimensional nickel electrode base, 10 denotes a mixed powder mainly composed of nickel hydroxide powder filled in the conductive electrode base, and 11 denotes a space part. The walls of the convex portions B and the concave portions C of the three-dimensional substrate formed by processing the nickel foil are inclined in one direction while having distortion, and the tips of the walls of the convex portions B and the concave portions C have a thin nickel thickness. And more strongly inclined in one direction. The distortion and the inclination of the tip suppress the separation of the filler such as the active material powder from the conductive electrode substrate. In addition, the inclination of the tip does not cause a short-circuit with the counter electrode due to the beard of the electrode, and the conductivity of the active material powder particles (near M in the figure) farthest from the conductive electrode substrate, which is a nickel substrate. The effect of shortening the shortest distance to the electrode base when it is not bent (near M '),
That is, it also has the effect of increasing the current collecting capability of the entire electrode.

In the case of a nickel positive electrode, when a general-purpose active material powder or the like is used, the distance from the conductive electrode substrate is reduced to 15%.
When the distance is more than 0 μm, the voltage and the active material utilization rate at the time of high-rate discharge slightly decrease, so that the conductive electrode substrate is hollow and has a three-dimensional thin film-like electrolyte-resistant metal formed by countless irregularities. It is a plate, and it is preferable that the shortest distance from the active material to the conductive electrode substrate is within 150 μm for most of the active material. Further, while the electrode substrate is conductive, the active material powder has almost no conductivity since Ni (OH) ₂ is used as a main material. It is preferable that about 5% by weight of the cobalt oxide is mixed in the active material powder paste. Further, in the case where further improvement in high-rate discharge characteristics is required due to the demand for higher power as a battery, the active material in the paste applied to the conductive electrode substrate three-dimensionally formed by the uneven shape is required. In the above, it is preferable that the shortest distance from the active material to the conductive electrode substrate is within 150 μm for most active materials. This is because if the content of the conductive powder or the cobalt oxide mixed in the active material powder to increase the current collecting property is increased, the content of the active material in the paste is reduced. More specifically, it is preferable that the size of the uneven portion and the pitch thereof are determined so that the distance between the conductive electrode substrate closest to M ′ in FIG. 1 is within 150 μm.

FIG. 2 is an overall view of the nickel positive electrode 1 having the structure as shown in FIG. 1, and is a thin nickel positive electrode having a thickness of 500 μm or less.

FIG. 3 shows an AA in which the thin nickel positive electrode of FIG. 2 is combined with a thin alloy negative electrode obtained by applying an MmNi5-based hydrogen storage alloy powder to a punching metal as in the prior art.
1 is a schematic view of a cylindrical sealed Ni / MH battery of a size. The battery components other than the electrodes are basically the same as the conventional battery structure.

Further, the conductive electrode substrate of the present invention comprises:
It is only necessary to have conductivity, and it is possible to process the distortion and inclination of the irregularities and the walls thereof after filling the active material powder, and it is not particularly limited, but is currently used for various battery electrodes. As the material of the conductive electrode substrate, at least one selected from the group consisting of nickel, copper, aluminum, lead and alloys containing these as main components is preferably used. Particularly, in a nickel electrode substrate for an alkaline storage battery, at least a surface of at least most of the surface is at least one selected from the group consisting of cobalt, calcium, titanium, silver, boron, yttrium, lanthanide, carbon and / or oxides thereof. Those in which the above-mentioned substances are arranged are more preferably used from the viewpoint of workability.

The thickness of the conductive electrode substrate three-dimensionally formed by the irregularities of the conductive electrode substrate according to the present invention may be adjusted after the powder mainly containing the active material powder or the quasi-active material powder is filled or applied. The thickness of the conductive electrode substrate is approximately 0.5 to 2.0 times the thickness of the final electrode. Is preferred. When the thickness of the conductive electrode substrate is less than 0.5 times the thickness of the final electrode, the high-rate discharge characteristics slightly decrease, and the active material powder or the quasi-active material powder and the conductive electrode It is not preferable because the active material powder and the like easily fall off due to a decrease in the contact area with the substrate. In addition, the thickness of the conductive electrode substrate is set to 2.
If it is 0 times or more, it is not preferable because unevenness of the metal foil becomes difficult. In particular, when the present invention is used for a nickel positive electrode, the thickness of the conductive electrode substrate is preferably 1.0 to 2.0 times the thickness of the final electrode.

In the present invention, the infinite number of hollow irregularities of the conductive electrode substrate are such that when one of the concave and convex portions is regarded as a three-dimensional shape, the concave and convex shapes are the conductive electrodes. It represents a concave portion and a convex portion which are not filled with the material constituting the base and have a shape having an inner wall surface.

The quasi-active material in the present invention is a material that absorbs and releases an active material such as Li (lithium) and H (hydrogen). The absorbed and released active material only needs to be released as an active material as a result, and may be included as an active material in the quasi-active material or as a compound of the active material and another material.

The filling or coating of the powder containing the active material powder or the quasi-active material powder as a main material in the present invention is not particularly limited, but it can be filled or coated by a known method.

The concave and convex portions of the concave and convex portions in the conductive electrode substrate of the present invention are not particularly limited, but may have a hollow conical shape, a hollow triangular pyramid, a quadrangular pyramid or a hexagonal pyramid. The shape may be a polygonal pyramid. The respective ends of the concave portion and the convex portion may be open or closed, but the holes are more likely to cause mechanical (physical) peeling of the coating layer containing the active material from the electrode substrate. This is preferable because it is easy to obtain strength against the electrode and uniformity of the electrode reaction occurring in the layer containing the active material on both the front and back surfaces of the conductive electrode substrate can be easily obtained.

The above-mentioned conductive electrode substrate in the present invention is a substrate having innumerable fine irregularities on most of its surface, which further provides electrical continuity between the conductive electrode substrate and an active material or a quasi-active material. It is preferable to improve the cycle life and the high rate charge / discharge characteristics because it is strengthened.

In the present invention, the arrangement pattern of most of the concavo-convex portions of the conductive electrode substrate is 3 to 3 in the longitudinal direction of the electrode.
At an angle in the range of 0 to 60 degrees, a row of a large number of concave portions or groups of concave portions and a row of a large number of convex portions or groups of convex portions are almost parallel to each other,
Preferably, they are provided alternately. Since the row of the large number of concave portions or the group of concave portions and the row of the large number of convex portions or the group of convex portions are provided alternately and substantially in parallel, the convex portions (concave portions) and the convex portions (concave portions) are provided. This is because the distance is easily kept constant, and the retention and conductivity of the active material powder and the like are uniformly provided throughout the electrode.

In the conductive electrode substrate according to the present invention, half or more of the concavo-convex portions or the concavo-convex portion groups which are closest to one of the protruding portions or the protruding portion group (concave portions or concave portion groups) of the conductive electrode substrate are formed. Group). At the same time, by providing a large number of rows of concave portions or groups of concave portions and a large number of rows of convex portions or groups of convex portions at an angle in the range of 30 degrees to 60 degrees as described above, the electrode can be formed at the time of pressure processing. This is because the conductive electrode base is prevented from being excessively stretched and unevenly stretched, and a uniform three-dimensional shape is formed in the electrode.

The distortion and inclination of the wall of the uneven portion in the conductive electrode substrate of the present invention are determined by the pre-pressing with two pairs of small-diameter rollers and the pressing for forming the final electrode with two pairs of large-diameter rollers. It can be formed by rolling mill processing. This rolling process is performed on the conductive electrode substrate filled or coated with the active material or the quasi-active material, so that the wall of the uneven portion is distorted in the thickness direction of the conductive electrode substrate and reaches the tip. Strongly tilted in one direction. Before the filling of the active material powder or the like, the thickness of the conductive electrode substrate is made sufficiently thick, and as shown in the partially enlarged view of FIG. In the case of filling, both surfaces of only the conductive electrode base may be crushed in advance so as to bend slightly in one direction. Further, in the above-mentioned rolling process, as a preliminary pressurization, passing a conductive electrode substrate filled with an active material or a semi-smooth material between slits provided with a doctor knife or a rubber spatula,
The layer containing the active material on the conductive electrode substrate may be rubbed with a rotating brush. If the conductive electrode substrate has a large three-dimensional structure, the preliminary pressing is omitted, and the roll pressing by a large-diameter roll is performed. By performing only the above, it is possible to configure the inclination of the uneven portion in one direction, particularly the strong inclination of the front end portion, as shown in the portion D of FIG.

The final electrode is preferably coated with a fine powder made of fluororesin after the electrode is processed. This is to make it more difficult for the active material powder or the like to fall off, and also to prevent the tips of the concave and convex portions of the conductive electrode base from protruding from the electrode like a beard and breaking through the separator. Therefore, as the type of synthetic resin used for coating the electrode,
Not only a fluororesin but also a resin having an electrolytic solution resistance and a binding property such as a polysulfone resin or a copolymer containing these as a main material can be applied.

When the paste-type thin electrode for a battery according to the present invention is processed into a spiral electrode, the tip of the concave and convex portion of the conductive electrode substrate becomes a mustache due to electrode extension due to repeated charging and discharging. In order to prevent this, it is preferable to be inclined in the direction perpendicular to the winding direction.

Further, in the secondary battery of the present invention, the above-mentioned electrode is inserted into the battery case, the positive electrode lead and the sealing plate are connected by spot welding or the like, and then the sealing plate is swaged at the opening of the battery case. Secondary battery.

The secondary battery of the present invention is obtained by inserting the above-mentioned electrode of the present invention into a container of a battery case having a desired outer diameter such as D, C, AA, AAA, AAAA and sealing the battery. Can be.

The battery case of the secondary battery according to the present invention comprises:
When the secondary battery of the present invention is used for applications where high capacity and light weight are desired, such as batteries for HEV, the thickness of the side wall surface (t
It is preferable that the thickness of the bottom (the ratio of _{t 2) (t 2 / t} 1) is used the weight battery case is 1.5 or more with respect to _1), there is room in the withstand voltage strength further to the battery internal pressure of the side wall of the container From the standpoint of ensuring that cracks generated by spot welding to the bottom are more reliable, the ratio of the thickness of the bottom (t ₂ ) to the thickness of the side wall surface (t ₁ ) (t ₂ /
More preferably, t ₁ ) is about 2.0. When the secondary battery of the present invention is used for an HEV battery or the like, the positive electrode terminal of another secondary battery adjacent to the bottom of the battery case of the secondary battery is directly or through a metal connector by welding depending on the use mode. Therefore, the battery case needs to have a thickness that does not deform or melt at the bottom of the battery case and that can withstand the spot welding with the connector for connection between cells. Therefore, in the battery case, the ratio (t ₂ / t ₁ ) of the thickness of the bottom portion (t ₂ ) to the thickness (t ₁ ) of the side wall surface of the battery case is set to 1.5 or more, so that the side of the battery case is Compared to a normal battery case where the wall thickness and the bottom thickness are almost the same, the thickness of the bottom is ensured as a thickness that can withstand spot welding and the thickness of the side wall is reduced to make the battery case It is possible to reduce the weight by about 30% without any change, and at the same time, increase the internal volume, so that the capacity of the secondary battery can be increased. The above welding is a known welding method, and the welding temperature of the spot
It is performed within the range of 00 to 3000 ° C.

In the secondary battery according to the present invention, the ratio (t ₂ ) of the thickness (t ₂ ) of the bottom portion to the thickness (t ₁ ) of the side wall surface.
/ T ₁ ) is at least 1.5 mm when used in an AAAA-size battery case having a thickness of about 0.2 mm or more.
By and when the thickness of the side wall surfaces using a battery case _{(t 2 / t 1 = 1.82} ) is 0.11mm is a same material, the thickness of the bottom be about 0.2mm The battery capacity can be improved by about 5% as compared with the case where a battery case (t ₂ / t ₁ = 1) having a side wall surface thickness of 0.2 mm is used.

The material of the battery case in the secondary battery of the present invention is not particularly limited. However, in the case of an alkaline storage battery, nickel-plated iron is used in terms of electrolytic solution resistance. It is preferable to use aluminum or aluminum alloy in addition to iron for weight reduction.

The above-mentioned battery case can be manufactured by a known method such as deep drawing. However, the thickness of the side wall is reduced and the thickness of the bottom (t ₂ ) with respect to the thickness (t ₁ ) of the side wall is reduced. Ironing to form a ratio (t ₂ / t ₁ ) of 1.5 or more
It is preferable to manufacture by drawing. When the battery case is manufactured by deep drawing in which the desired shape of the battery case is approached in a number of times, the thickness of the bottom portion and the side wall surface are generally almost equal. 10
As shown in FIG. 5, since the bottomed cylindrical container 14 is formed by extruding and pressing a metal plate material once with the spindle 13, the battery case is desired by adjusting the interval between the spindle and the mold 15. The battery case having the thickness of the side wall surface can be easily formed.

In the battery case of the secondary battery according to the present invention, a thick portion is provided inside the battery case along a boundary between the side wall surface and the bottom portion of the battery case in order to secure mechanical strength. Is preferred. The thick part is shown in FIG.
In the portion indicated by R in FIG. 1, the outer periphery of the tip end portion of the spindle used when creating the battery case is chamfered, so that the corresponding thick portion of the battery case can be easily provided. Although the effect is recognized even if a slightly chamfered spindle is used, 1A chamfering in an AA size battery case is appropriate without reducing the battery capacity.

In the secondary battery of the present invention, the weight of the battery can be reduced by using the above electrodes. However, the side wall surface is extremely thin, and the thickness (t ₁ ) of the side wall surface with respect to the thickness (t ₁ ) of the bottom portion. by a ratio of _{2) (t 2 / t 1} ) is used the battery case is 1.5 or more, it is possible to provide a more lightweight rechargeable battery.

[0049]

Next, specific examples of the present invention will be described.

(Production Example) As shown in FIG. 10, a 0.3 mm thick nickel-plated steel plate (plated thickness: 1 μm) punched in a circular shape was formed by a single ironing-drawing process using a known spindle 13. A cylindrical container 14 was obtained. Specifically, the dimensions of the bottomed cylindrical container are an outer diameter of 14 mm, a side thickness of 0.16 mm, a bottom, and a thickness of 0.25 mm. In order to suppress a decrease in physical strength at the boundary between the side surface and the bottom, a thick portion R is preferably provided inside the boundary.

(Example 1) A hoop-shaped nickel foil having a thickness of 30 µm was pressed by being passed between molds provided with conical irregularities (or between rollers) to thereby apply pressure to the nickel electrode base 9 shown in FIG. A three-dimensional conductive electrode substrate provided with countless minute hollow chimney-shaped irregularities was manufactured. 5A and 5B, which are partial enlarged views of the nickel electrode substrate, are shown as examples of possible types of the pattern of the concave and convex portions of the nickel electrode substrate 9 in FIG. B and C in the figure indicate a convex portion and a concave portion, respectively. In FIG. 5 (a), all of the protrusions (concave portions) closest to the convex portions (concave portions) are concave portions (convex portions).
In (b), four of the six closest to the convex portion (concave portion) are concave portions (convex portions). In the present embodiment, the pattern shown in FIG. In (a), all of the protrusions (recesses) closest to the protrusions (recesses) are the recesses (convexities), and the diameter of the hollow substantially conical portion of the recess (convexity) is 60 to 80 μm at the root and 35 at the tip.
The thickness of the latter was reduced by strongly processing with two upper and lower flat plate dies having irregularities to make the latter most thin with holes. The thickness of the conductive electrode substrate three-dimensionally formed by the concave and convex portions was 500 μm, which was about 100 μm thicker than the final electrode thickness. The pitch between the convex and concave (or the pitch between the concave and convex) was 150 to 250 μm in both the longitudinal direction of the hoop and the direction perpendicular thereto. The angle (m) of the row of the protrusions (recesses) with respect to the longitudinal direction of the conductive electrode base is about 45.
Degrees. In FIG. 4, reference numeral 12 denotes a portion not subjected to such concavo-convex processing, a part of which is used for an electrode lead. The non-processed portion 12 is provided for the purpose of relieving the distortion of the active material and the like due to the electrode extension at the time of pressing, and the non-processed portion 12 is slightly corrugated in the longitudinal direction of the conductive electrode base. Processed.

A paste of active material powder was filled in a nickel electrode substrate 9 provided with countless minute hollow chimney-like irregularities so as to form the pattern shown in FIG. 5A. The active material is mainly nickel hydroxide, but is a spherical powder having a particle diameter of about 10 μm in which about 1 wt% of cobalt and about 3 wt% of zinc are dissolved in nickel hydroxide. Powder was used. This active material powder was mixed with about 1% by weight of carboxymethyl cellulose and about 0.1% of polyvinyl alcohol.
wt% into a solution and paste, and about 3 wt% and about 2 wt% of cobalt oxide (CoO) and zinc oxide (ZnO) are added to nickel hydroxide, respectively.
The final paste was used. FIG. 5 is a partially enlarged view showing a state where the mixed powder paste of the active material is filled in the nickel electrode substrate 9 and then substantially dried.

Next, between the two pairs of rollers having a diameter of about 30 mm shown in S and S 'in FIG. 6 which are filled with the mixed powder paste of the active material and rotate the dried nickel electrode substrate at a relatively high speed. And gently pressurized at a rotation speed of 10 rotations / sec while rubbing the surface, and then the diameter indicated by N and N 'was about 450.
The roller was strongly pressed at a rotation speed of 50 to 100 mm / sec between rollers having a thickness of 400 mm to a thickness of 400 μm. The nickel electrode substrate occupies only 3 parts of the nickel positive electrode.
vol%, the amount of the metal is about half that of the 6-9 vol% of the conductive electrode substrate in the normal 3DM type positive electrode, so the conventional lightest weight It became a lighter and thinner electrode than the 3DM type.

This thin electrode is 40 mm wide and 150 m long.
m, and then immersed in a suspension of a fluororesin fine powder having a concentration of about 3 wt%, and then dried to form a nickel positive electrode.
Normal MmNi5 μm, width 40 mm, length 210 mm
AA obtained in the production example in combination with a hydrogen storage alloy negative electrode
The battery was inserted into a battery case having a size, and sealed with a gasket 5 and a sealing plate 6 also serving as a known positive electrode terminal in FIG. 3, thereby producing an AA-size cylindrical sealed Ni / MH battery having a theoretical capacity of 1550 mAh for the positive electrode. In addition, a non-woven fabric of sulfonated polyolefin resin fiber having a thickness of 120 μm is used for the separator, and the electrolyte is about 30 wt% KO.
H aqueous solution was used.

The cylindrical sealed Ni / MH battery of the secondary battery in the present embodiment is used especially for the purpose of clarifying the characteristics of the nickel positive electrode, that is, in order to avoid being restricted by the characteristics of the negative electrode as much as possible. The designed capacity balance of the normal positive and negative electrodes was slightly changed, and the theoretical capacity of the negative electrode was 1.8 times larger than the theoretical capacity of the positive electrode. Incidentally, that of a general-purpose battery is 1.3 to 1.6 times.

FIG. 8 shows the average value of the high-rate discharge characteristics of 10 cells of this battery by q. The discharge voltage shown on the vertical axis is the voltage at the time of 50% discharge of the theoretical capacity.

(Comparative Examples 1 to 3) As Comparative Example 1, a conductive electrode substrate pressed between ordinary flat plates, that is, a conductive electrode which is not subjected to an operation of bending the tip of the uneven portion in one direction as in the present invention. The results of examining the high-rate discharge characteristics of a secondary battery and examining the high-rate discharge characteristics in the same manner as in Example 1 except that the negative electrode substrate was used are shown by p in FIG.

As Comparative Example 2, a 3DM type electrode was prepared in the same manner as in Example 1 except that a normal foamed nickel porous body (trade name: Celmet, manufactured by Sumitomo Electric Industries, Ltd.) was used for the conductive electrode substrate. The result of examining the high-rate discharge characteristics when a secondary battery was prepared in the same manner as in Example 1 except that the nickel positive electrode was used was shown by o in FIG.

Comparative Example 3 In the case of Example 1 except that a conductive electrode substrate in which the pitch between one row of convex portions and the next row of convex portions was 400 μm, which was about twice that of Example 1, was used. The results of examining the high-rate discharge characteristics of a secondary battery in the same manner as described above are shown by n in FIG.

(Evaluation and Examination of Example 1 and Comparative Examples 1 to 3) As a result of Example 1 and Comparative Examples 1 to 3, in the case of this example, the voltage was almost It was excellent. In particular, the effect of setting the distance between adjacent convex and convex portions, that is, the distance between the row of convex portions and the next row of convex portions to 200 μm is great. That is, in this case, the distance between the farthest active material powder particles and the conductive electrode substrate shown by M ′ in FIG. 1 falls within the range of 70 to 100 μm. The secondary battery p of Comparative Example 1 also exhibited excellent high-rate discharge characteristics, but as shown in FIG. 9, 1C discharge and 1C charge (110% charge of discharge capacity) were repeated at 20 ° C. In the cycle life test, the secondary battery of the present invention showed a small capacity reduction even at 700 cycles, but showed a large capacity deterioration at 500 cycles. In this case, both of the batteries of Example 1 and Comparative Example 1 were tested with 10 cells. FIG. 9 shows two intermediate cells each showing the upper and lower characteristics, and the remaining intermediate characteristics were shown. The average value of 6 cells was used. By the way, in the battery at p, two out of ten cells short-circuited at around 100 cycles. The effect due to the bending of the tip of the unevenness is extremely large.

That is, when the structure of the conductive electrode substrate according to the present invention is employed, excellent high-rate discharge characteristics can be obtained, and the retention of powders such as active materials is improved. Is less likely to occur (high reliability).

Further, the core material of the alloy negative electrode in the secondary battery of this embodiment can be obtained by adopting the nickel electrode substrate of the present invention.
The characteristics of q in FIGS. 8 and 9 are slightly improved. That is, it was found that a thin alloy negative electrode had the same effect. Further, the same effect can be expected for a Li secondary battery requiring high-rate discharge, based on the same principle, for high-rate discharge characteristics, retention of active material, cycle life, and the like.

Example 2 Example 1 was the same as Example 1 except that the nickel foil was subjected to the pattern processing of the partially enlarged view (b) of FIG. In the same manner as in the case of
/ MH battery was prepared, and high-rate discharge characteristics and cycle life were examined. Also in this case, the pitch between the convex and convex portions adjacent beyond the concave portion or between the concave portions and concave portions adjacent beyond the convex portion is 200 μm.
And The angle m 'between the row of concave portions or the row of convex portions and the length direction of the electrode was 30 degrees.

(Evaluation and Examination of Example 2) Also in the case of this example, the high rate discharge characteristics and the cycle life were excellent, and
The same characteristics as described above were obtained.

A similar nickel foil was formed by corrugating the electrode substrate in the longitudinal direction or in the direction perpendicular to the longitudinal direction (in this case, the angle corresponding to m ′ was 90 ° or 0 °). The nickel electrode used as the conductive electrode substrate
During the spiral processing, the active material powder and the like were peeled off, and the active material utilization rate significantly decreased from the initial stage.

According to this embodiment, the row of the convex portions or the concave portions is
At least 30 to 60 degrees with respect to the longitudinal direction, it is possible to prevent the nickel electrode base from being partially or entirely made excessively two-dimensional even in the compression at the time of roll pressing, and the nickel base remains disposed on the entire electrode This is considered to be due to its excellent current collecting properties.

(Example 3) As a conductive electrode substrate, when processing nickel, a thick nickel plate before processing was coated with cobalt foil on both the front and back surfaces and rolled as a whole to be processed into nickel foil. Was used in the same manner as in Example 1 except that Ni was used for the conductive electrode substrate.
/ MH battery was prepared, and high rate discharge characteristics were examined. In addition, the amount of cobalt was set to 0.5 wt% with respect to nickel. In this embodiment, the electron conductivity of cobalt oxide generated on the surface of the conductive electrode substrate is superior to that of nickel, so that the high-rate discharge characteristics are slightly improved compared to Example 1.

(Examples 4 to 9) As Example 4, a cylindrical sealed Ni / MH battery was manufactured in the same manner as in Example 3 except that a calcium foil was attached instead of a cobalt foil attached to the surface of a nickel foil. It was created. Also, instead of the cobalt foil in Example 3, titanium, silver, yttrium,
Cylindrical sealed Ni / MH batteries were prepared in the same manner as in Example 3 except that a lanthanide or carbon foil was used. Cylindrical sealed Ni in each embodiment
When the cycle life and high-rate discharge characteristics of the / MH battery were examined in the same manner as in Example 1, it was found that the cycle life and the high-rate discharge characteristics were slightly improved. In each case, the effect of improving the variation in cycle life was recognized when a further small amount of boron was present.

Example 10 A cylindrical sealed Ni / MH battery was prepared in the same manner as in Example 1, except that the surface of the nickel foil of Example 1 was roughened with countless fine irregularities. When the cycle life and high-rate discharge characteristics were examined, improvements in cycle life and high-rate discharge characteristics close to those of Example 3 were recognized.

Example 11 A hoop-shaped nickel foil having a thickness of 30 μm was pressurized by being passed between molds having conical concavities and convexities (or between rollers) to form a nickel electrode base 9 shown in FIG. Fig. 5 (a) shows countless hollow and conical irregularities
A three-dimensional conductive electrode substrate provided in the above pattern was produced. The thickness of the conductive electrode substrate three-dimensionally formed by the concavo-convex portions is 140 μm, and the pitch between the concavities and convexities (or the pitch between the concavities and convexities) is 14 in both the longitudinal direction of the hoop and the direction perpendicular thereto.
It was set to 0 μm. About 1 wt% of carboxymethyl cellulose, about 1 wt% of carboxymethyl cellulose, and about 10 wt% of a spherical particle powder obtained by dissolving about 1 wt% of cobalt and about 3 wt% of zinc with respect to nickel hydroxide are dissolved in the electrode substrate. A paste and a solution in which about 0.1% by weight of vinyl alcohol is dissolved, and further, cobalt oxide (CoO) and zinc oxide (Z
nO) and about 3 wt% with respect to nickel hydroxide, respectively.
And a paste obtained by adding about 2% by weight of the mixture, and then dried to obtain a thin electrode as a final electrode having the same thickness as the conductive electrode substrate. In this final electrode, a concavo-convex pattern was arranged such that the distance from the active material farthest from the conductive electrode substrate to the conductive electrode substrate was 100 μm.

(Example 12) The thickness of the conductive electrode substrate three-dimensionally formed by the concavo-convex portions was set to 210 μm, and the pitch between the concavities and convexities (or the pitch between the concavities and convexities) was set to 210 μm in both the longitudinal direction of the hoop and its perpendicular direction. A final electrode was obtained in the same manner as in Example 11 except for performing the above. In this final electrode, a concavo-convex pattern was arranged such that the distance from the active material farthest from the conductive electrode substrate to the conductive electrode substrate was 150 μm.

(Comparative Example 4) The thickness of the conductive electrode substrate three-dimensionally formed by the concavo-convex portions was 280 μm, and the pitch between the concavities and convexities (or the pitch between the concavities and convexities) was 280 μm in both the longitudinal direction of the hoop and its perpendicular direction. A thin electrode as a final electrode was obtained in the same manner as in Example 11 except for performing the above. In this final electrode, a concavo-convex pattern was arranged such that the distance from the active material farthest from the conductive electrode substrate to the conductive electrode substrate was 200 μm.

(Comparative Example 5) The thickness of the conductive electrode substrate three-dimensionally formed by the concavo-convex portions was 420 μm, and the pitch between the concavities and convexities (or the pitch between the concavities and convexities) was 420 μm in the longitudinal direction of the hoop and in the direction perpendicular thereto. A thin electrode as a final electrode was obtained in the same manner as in Example 11 except for performing the above. In this final electrode, a concavo-convex pattern was arranged such that the distance from the active material farthest from the conductive electrode substrate to the conductive electrode substrate was 300 μm.

(Evaluation of Examples 11 and 12 and Comparative Examples 4 and 5) For the thin electrodes obtained in Examples 11 and 12 and Comparative Examples 4 and 5, a half-cell with a nickel screen as a counter electrode was prepared. The discharge rate characteristics were examined.
FIG. 12 shows the result of 5C discharge, and FIG. 1 shows the result of 5C discharge.
3 is shown. The results of Example 11 are e and i, and Example 12
Are f and j, the result of Comparative Example 4 is g and k, and the result of Comparative Example 5 is h and l. The thin electrodes of Example 11 and Example 12 were good with respect to the high-rate discharge characteristics at 0.5 C discharge and 5 C discharge without causing an extreme decrease in voltage and capacity. On the other hand, the secondary batteries using the thin electrodes of Comparative Examples 4 and 5 had good high-rate discharge characteristics at 0.5 C discharge. , Extreme voltage and capacity drop. In Examples 11 and 12, excellent high-rate discharge characteristics were obtained by keeping the distance from the active material powder particles farthest from the conductive electrode substrate to the conductive electrode substrate within 150 μm.

[0075]

As described above, the use of the thin nickel positive electrode according to the present invention makes it possible to reduce the weight of Ni / MH, which is lightweight, excellent in high-rate discharge characteristics, cycle life and reliability, and low in cost.
A battery can be obtained, and the thickness of the side wall surface (t
It is possible to obtain a Ni / MH batteries are high capacity lightweight by the thickness of the bottom (the ratio of _{t 2) (t 2 / t} 1) is used the battery case is 1.5 or more with respect to ₁₎ .

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a nickel positive electrode according to one embodiment of the present invention.

FIG. 2 shows a nickel positive electrode according to an embodiment of the present invention. A-
The cross section of A is shown in FIG.

FIG. 3 shows a cylindrical sealed Ni / M according to an embodiment of the present invention.
H battery (AA size).

FIG. 4 is a hoop-shaped electrode substrate used for a nickel positive electrode according to one embodiment of the present invention.

5 (a) and 5 (b) show two examples of a pattern of unevenness processing.

FIG. 6 shows a step of pressing a nickel positive electrode according to an embodiment of the present invention.

FIG. 7 is a cross-sectional view of an electrode after filling of paste such as active material powder.

FIG. 8 shows high-rate discharge characteristics of a cylindrical sealed Ni / MH battery (AA size) using a nickel positive electrode according to one embodiment of the present invention.

FIG. 9 is a cycle life characteristic of a cylindrical sealed Ni / MH battery (AA size) using a nickel positive electrode according to an embodiment of the present invention.

FIG. 10 Ironing-drawing process.

FIG. 11 is an enlarged sectional view of a battery case manufactured by ironing and drawing.

FIG. 12 shows a high-rate discharge characteristic (half cell) of a nickel positive electrode according to one embodiment of the present invention.

FIG. 13 shows a high-rate discharge characteristic (half cell) of a nickel positive electrode according to an embodiment of the present invention.

[Explanation of symbols]

 1: Nickel positive electrode 2: Hydrogen storage alloy negative electrode 3: Separator 4: Battery case 5: Gasket 6: Positive electrode terminal 7: Safety valve 8: Positive electrode lead terminal 9: Nickel electrode base 9 ': Nickel electrode base not processed 10: Mixed powder mainly composed of active material 11: Space portion 12: Non-processed portion 13: Spindle 14: Bottomed cylindrical container 15: Mold 16: Battery case side wall surface 17: Battery case bottom surface B: Convex portion C: Concave portion D: Tip of uneven portion M, M ': Mixed powder farthest from substrate S, S': Small-diameter roller N, N ': Large-diameter pressure roller R: Thick portion

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 4/62 H01M 4/62 C 4/66 4/66 A F term (Reference) 5H011 AA01 AA03 AA09 CC06 DD03 DD26 5H017 AA01 AA02 AA03 BB06 BB08 BB11 BB13 BB15 BB19 CC01 DD01 DD08 EE04 HH03 5H022 AA01 AA04 AA09 BB01 BB11 CC10 EE01 5H050 AA02 AA07 AA14 AA19 BA08 DA04 DA09 DA20 EA23 FA03 GA03 FA03 GA09

Claims (21)

[Claims] 1. A thin electrode in which a conductive electrode substrate having a three-dimensional structure is filled or coated with a powder mainly containing an active material powder or a quasi-active material powder, wherein the conductive electrode substrate comprises (a) And (b) a thin film-shaped electrolyte-resistant metal plate having a hollow and innumerable irregularities, and (b) a thickness of the conductive electrode substrate three-dimensionally formed by the irregularities is substantially equal to the thickness of the electrode. Yes,
(C) More than half of the closest unevenness portion or the closest unevenness portion group with respect to one protrusion or a group of protrusions or one recess or a group of recesses is a recess or a group of recesses or a group of the protrusions or protrusions; A paste-type thin electrode for a battery, wherein the wall of the uneven portion is distorted in the thickness direction of the conductive electrode substrate, and is strongly inclined in one direction toward the tip. 2. The battery according to claim 1, wherein the conductive electrode substrate is a rough surface having a metal as a main component and having innumerable fine irregularities on most surfaces. Paste type thin electrode. 3. The conductive electrode substrate has nickel as a main component, and at least most of its surface is made of cobalt, calcium, titanium, silver, boron, yttrium, lanthanide, carbon and / or an oxide thereof. 4. The paste-type thin electrode for a battery according to claim 1, wherein at least one substance selected from the group is disposed. 4. The conductive electrode substrate according to claim 1, wherein the thickness of the vicinity of the top end of the concave / convex portion of the conductive electrode substrate is thinner toward the front end, and at least half or more of the front end have holes. The paste-type thin electrode for batteries according to 1. 5. The arrangement pattern of most of the concavo-convex portions on the conductive electrode base is 30 ° to 30 ° with respect to the length direction of the electrode.
An angle in the range of 60 degrees, and a row of a large number of concave portions or groups of concave portions and a row of a large number of convex portions or groups of convex portions are substantially parallel to each other,
The paste-type thin electrode for a battery according to claim 1, which is provided alternately. 6. The paste-type thin electrode for a battery according to claim 1, wherein each of the concavo-convex portions in the concavo-convex portion is a hollow cone, a triangular pyramid, a quadrangular pyramid, a hexagonal pyramid, or an octagonal pyramid. 7. The conductive electrode substrate according to claim 1, wherein the tips of the convex portions and the concave portions which are inclined in one direction in the conductive electrode base are inclined so as to cover the gaps between the adjacent convex portions or concave portions. Paste type thin electrode for batteries. 8. The paste-type thin electrode for a battery according to claim 1, wherein the surface of the electrode is covered with a fine powder of an electrolytic solution-resistant synthetic resin. 9. The battery according to claim 1, wherein the spirally configured electrode has an unevenness in one direction in the uneven portion of the conductive electrode substrate, which is substantially perpendicular to the winding direction. Paste type thin electrode. 10. A thin electrode in which a conductive electrode substrate having a three-dimensional structure is filled or coated with a powder mainly comprising an active material powder or a quasi-active material powder, wherein the conductive electrode substrate is hollow and innumerable. Is a thin film-shaped electrolyte-resistant metal plate three-dimensionally formed by the uneven portions, wherein the longest distance between the conductive electrode substrate and the filled or coated active material powder or quasi-active material powder particles is 150 μm or less. A paste-type thin electrode for a battery, characterized in that the electrode is maintained at a low temperature. 11. A conductive electrode substrate having a three-dimensional structure, wherein (a) irregularities are formed at least at both ends along a longitudinal direction, excluding portions which are not irregularities having a desired width, and (b) (C) The thickness of the conductive electrode substrate three-dimensionally formed by the unevenness is 0.5 to 2.0 times the thickness of the final electrode. A thin film-like electrolytic solution-resistant metal plate, wherein (d) at least half of the closest irregularities or groups of one convex or convex group or one concave or concave group are concaves or concave groups; Alternatively, a hoop-shaped conductive electrode substrate that is a convex portion or a group of convex portions is filled or coated with a paste-like powder of a mixed powder mainly containing an active material or a quasi-active material mainly in a hollow portion of the concave and convex portion. The coated conductive electrode substrate is placed between rolling rolls. A method for producing a paste-type thin electrode for a battery, comprising forming the paste-type thin electrode for a battery after press-molding the same. 12. The conductive electrode substrate is provided with an uneven portion by performing an uneven process through a mold that is subjected to an uneven process and is engaged with the upper and lower molds or a roller that has been subjected to a similar process, or A metal substrate having an uneven portion formed by an electrolytic deposition method, wherein a number of concave portions or rows of concave portions and a large number of convex portions are formed at an angle in a range of 30 to 60 degrees with respect to a longitudinal direction. 12. The method for producing a paste-type thin electrode for a battery according to claim 11, wherein the rows of the convex groups are arranged alternately in parallel at substantially constant intervals. 13. The method for producing a paste-type thin electrode for a battery according to claim 12, wherein the conductive electrode substrate is formed by pressing and bending both surfaces in one direction. 14. The method according to claim 1, wherein the pressing between the rolling rolls is performed at least twice, and the pressing is performed at a relatively high speed in a direction opposite to the advancing direction of the electrode between the rollers having a small diameter. The battery according to claim 11, wherein the pressure is applied at a low pressure, and the subsequent pressure is applied at a lower speed and a higher pressure between the rollers having a larger diameter than the former. Manufacturing method of paste type thin electrode. 15. The method according to claim 11, wherein the electrode filled or coated with the active material or the quasi-active material is lightly pressed while rubbing the surface with a doctor knife or a brush, and then formed under pressure. The method for producing a paste-type thin electrode for a battery according to the above. 16. After cutting to a desired size, the electrode is immersed in a liquid in which fine synthetic resin powder is dispersed, or the liquid is sprayed on the electrode surface, and the fine synthetic resin powder is thinly applied to the electrode. The method for producing a paste-type thin electrode for a battery according to claim 11, wherein the electrode is coated. 17. The method according to claim 16, wherein the synthetic resin is a fluororesin, a polysulfone resin, or a copolymer containing them as a main material. 18. A thin electrode in which a conductive electrode substrate having a three-dimensional structure is filled or coated with a powder mainly containing an active material powder or a quasi-active material powder is sealed in a battery case as a positive electrode and / or a negative electrode. Wherein the conductive electrode substrate (a) has a hollow and innumerable irregularities,
(B) a thin film of an electrolytic solution-resistant metal plate in which the thickness of the conductive electrode substrate three-dimensionally formed by the uneven portions is almost the thickness of the electrode; and (c) one convex portion or one convex portion More than half of the closest concavo-convex portion or the closest concavo-convex portion group to one or more concavities or concavity portions is a concavity or a concavity group or a protruding portion or a protruding portion group. A secondary battery comprising: a paste-type thin electrode for a battery that is distorted in the thickness direction of the conductive electrode substrate and is strongly inclined in one direction toward the tip. 19. In the battery case, the thickness (t ₂ ) of the bottom portion is a thickness that can withstand welding, and the ratio (t ₂ ) of the thickness (t ₂ ) of the bottom portion to the thickness (t ₁ ) of the side wall surface. ₂ /
19. The method according to claim 18, wherein t ₁ ) is 1.5 or more.
2. The secondary battery according to 1. 20. The secondary battery according to claim 19, wherein a thick portion is provided inside the battery case at a boundary between a side wall surface and a bottom portion of the battery case. 21. The secondary battery according to claim 19, wherein a positive terminal of an adjacent secondary battery is welded to the bottom of the battery case directly or via a metal connector.