JPH09161793A - Manufacture of electrode for battery and electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture an electrode uniformly containing an electrode active material by securing sufficient electrode capacity while holding electric conductivity and durability of the electrode. SOLUTION: A current collecting body composed of a nickel foil is prepared (process S100), and at the same time, paste is manufactured (process S102) by adding water to a positive electrode active material such as nickel hydroxide. The manufactured paste is applied to the current collecting body (process S104), and this is dried, and is formed as an active material organizer (process S106). Autocatalytic electroless plating is applied to this active material organizer (process S108), and a positive electrode to be used in a nickel-hydrogen storage battery is completed (process S110). In this plating process, nickel being plating metal grows from a nickel foil surface while filling up a clearance between positive electrode active material particles dispersed in the active material organizer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a battery electrode and an electrode, and more particularly, to an electrode in which an electrode active material and a conductive material are mixed in a predetermined ratio around a conductive current collector. The present invention relates to a method for manufacturing a battery electrode forming an operating part and the electrode.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing such a battery electrode, foamed nickel having three-dimensionally continuous fine pores formed therein is used as a substrate, and a paste is formed in the fine pores of the foamed nickel. There is known a method of filling the electrode active material. In a battery electrode, in order to react the electrode active material efficiently, it is necessary that the electrode active material and the conductive material are appropriately mixed. Further, in order to improve the energy density of the battery, it is important to retain as much electrode active material as possible in the electrode. By adopting the method of filling the paste-like electrode active material into the fine pores of nickel foam, which is the current collector, it is possible to increase the filling rate of the electrode active material, and at the same time, inside the conductive current collector. It is possible to obtain an electrode in which the electrode active material is mixed appropriately.

For example, nickel-hydrogen batteries and nickel-
The nickel electrode, which is the positive electrode of a cadmium battery, can be prepared by rubbing a paste material mainly composed of an electrode active material such as nickel hydroxide into the fine pores of nickel foam or by blowing it into the fine pores with a nozzle. Being manufactured.

[0004]

However, as described above, when the electrode active material paste material is filled in the fine pores of the current collector, the filled electrode may be formed by any method such as rubbing or blowing. Since air bubbles partially remain in the active material paste, it is difficult to sufficiently fill the inside of the current collector with the electrode active material paste material. Therefore, a step of pressing the electrode filled with the electrode active material paste material is necessary to remove the air bubbles remaining inside the current collector. However, even if the electrode is pressed in this way, if the bubbles are not evenly filled when the paste is filled, the mixed state of the electrode active material in the pressed electrode is also non-uniform, so that this electrode is incorporated into a battery. The reaction that occurs when the device is operated at is also non-uniform depending on the site inside the electrode.

As a method for improving the filling efficiency of such a paste material, a method of filling the paste material under reduced pressure in vacuum has been proposed (for example, JP-A-4-10).
No. 355, etc.), but such a method may be difficult to adopt because it causes an increase in the size of the device. Further, in the method of filling the electrode active material paste material in the fine pores of the current collector, whichever manufacturing method is used, the proportion of the electrode active material is increased to a predetermined amount or more because the conductive agent or the binder is used. However, there is a problem in that it hinders the improvement of the electrode capacity. The conductive agent is for assisting the transfer of electrons between the electrode active material filled in the fine pores of the current collector and the current collector, and the binder is the electrode active material paste for the current collector. It is to be bound in the fine holes. Therefore, both the conductive agent and the binder have heretofore been essential elements in the electrode active material paste.

The method of manufacturing an electrode for a battery and the electrode of the present invention solve these problems, maintain the conductivity and durability of the electrode, secure a sufficient electrode capacity, and make the electrode active material uniform. The purpose of the present invention is to easily manufacture the electrode included in, and the following constitution is adopted.

[0007]

Means for Solving the Problem and Its Action / Effect According to the method of manufacturing an electrode for a battery of the present invention, a conductive current collector is arranged at the base, and an electrode active material is contained around the current collector. A paste prepared by kneading fine particles with a predetermined liquid is applied, the paste is dried to evaporate the predetermined liquid, and the fine particles containing the electrode active material are held around the current collector with a predetermined gap therebetween. The present invention is to produce an active material molded body having the above-mentioned structure, perform plating on the active material molded body, and deposit a conductive plating metal between the fine particles containing the electrode active material in the active material molded body. And

In the method for producing a battery electrode of the present invention, a paste obtained by kneading fine particles containing an electrode active material with a predetermined liquid is applied around a conductive current collector and dried to form a paste. The liquid used is evaporated to prepare an active material molded body in which fine particles containing the electrode active material are held around the current collector with a predetermined gap therebetween. The active material molded body is plated to deposit a conductive plated metal between the fine particles containing the electrode active material. That is, according to the method for producing a battery electrode of the present invention, it is not a conventional practice to form a void inside a conductive metal and then pack the electrode active material in the void. Is provided, and a conductive metal is deposited in this void.

In such an electrode manufacturing method, the active material molded body is plated, and
Since the conductive plating metal is deposited between the fine particles containing the electrode active material, sufficient and uniform conductivity can be ensured inside the electrode. At this time, since the electrode active material is held by the deposited plating metal, it is possible to make the electrode excellent in durability. Here, since the active material molded body is dried while the electrode active material is dispersed in the paste, the dispersion state of the electrode active material in the finished electrode is also uniform. Furthermore, since this manufacturing method only involves simple operations such as applying paste and plating,
There is no need to prepare special processes or equipment.

Here, the fine particles forming the paste may be composed only of the electrode active material. In the battery electrode manufacturing method of the present invention, since the electrode active material is held by the plating metal deposited between the electrode active materials, sufficient conductivity and durability are achieved. Therefore,
It is not necessary to add a conductive agent for increasing the conductivity of the electrode and a binder that helps the paste to bind to the electrode when the paste is prepared. Therefore, the ratio of the electrode active material does not decrease, and the electrode capacity does not decrease. Of course, a predetermined amount of binder may be added within a range where the electrode capacity is acceptable. In this case,
By adding the binder, the durability of the active material molded body before plating can be improved.

The predetermined liquid used for forming fine particles containing the electrode active material into a paste does not cause a chemical reaction between the fine particles constituting the paste and the current collector, and is kneaded by mixing with the fine particles. Any material can be used as long as it can produce a paste and can be evaporated from the produced paste.

Further, in the method for producing a battery electrode of the present invention, it is also preferable that the plating applied to the active material molded body is electrocatalytic electroless plating. At this time, the produced active material molded body is subjected to autocatalytic electroless plating to deposit a conductive metal between the electrode active materials of the active material molded body. Therefore, when plating the active material molded body, it is not necessary to prepare an external power source to apply a current, and it is sufficient to immerse the active material molded body in a predetermined plating solution. In addition, since self-catalytic electroless plating can form a dense film having an arbitrary thickness, it is possible to fill the space between the electrode active materials forming the paste with a conductive metal without any gap. Furthermore, in electrocatalytic electroless plating, since no current flows in the plating solution, there is no effect of current distribution due to the shape of the object to be plated, and there is no difference between the electrode active materials in the active material molded body. Uniform plating is possible even with complicated shapes.

In the case of performing self-catalytic electroless plating as described above, it is also preferable that the current collector is made of a metal having catalytic activity in electroless plating. When a metal having electrical conductivity and catalytic activity is used as the current collector, it is not necessary to subject the current collector to catalysis as a pretreatment for plating before applying the paste to the current collector.

In the method for producing a battery electrode of the present invention, the predetermined liquid used for forming the paste containing the electrode active material may be water. In such a case, the paste containing fine particles containing the electrode active material can be formed using an inexpensive and safe liquid, and the paste can be easily dried.

Further, in the method for producing a battery electrode according to the present invention, the current collector is made of nickel, the electrode active material is nickel oxyhydroxide and / or nickel hydroxide, and The plating performed as described above may be nickel plating. In such a case, it is a positive electrode such as a nickel-hydrogen storage battery or a nickel-cadmium storage battery, and the conductivity and durability are maintained, a sufficient electrode capacity is ensured, and a nickel electrode containing an electrode active material uniformly. Can be easily manufactured.

In the electrode of the present invention, a conductive current collector is arranged at the base, and an electrode operating portion in which an electrode active material and a conductive material are mixed at a predetermined ratio is provided around the current collector. The gist of the electrode to be formed is that the electrode operating portion holds the electrode active material dispersed at a predetermined interval by a conductive plating metal deposited between the electrode active materials.

In such an electrode, a reaction occurs in the electrode active material arranged around the conductive current collector. At this time, electrons move between the electrode active material and the current collector through the conductive plated metal. Since the electrode active material is held by the conductive plating metal, uniform and sufficient conductivity and durability are realized in the entire electrode. Further, since the electrode active material is dispersed at a predetermined interval, it is possible to make the amount of the electrode active material of the electrode sufficient and to realize a sufficient electrode capacity.

Here, if the predetermined interval in which the electrodes are dispersed is small, the proportion of the electrode active material in the electrodes is large, and the electrode capacitance is large. On the other hand, if the predetermined distance in which the electrodes are dispersed is increased, the ratio of the conductive material in the electrode operating part is increased, so that the conductivity of the electrode is improved, and the electrode active material is firmly held by the plating metal. Therefore, the durability of the electrode is improved. The proportion at which the electrode capacity and durability are appropriately achieved may be selected according to the size, shape, and structure of the battery to be manufactured.

In the electrode of the present invention, the current collector is made of nickel, the electrode active material is nickel oxyhydroxide and / or nickel hydroxide, and conductive plating deposited between the electrode active materials. The metal may be nickel. In such a case, it should be used in a nickel-hydrogen storage battery or a nickel-cadmium storage battery as a nickel electrode that maintains conductivity and durability, secures sufficient electrode capacity, and uniformly contains an electrode active material. You can

[0020]

Other Embodiments of the Invention The present invention can also take the following other embodiments. A first aspect is a method for producing a negative electrode of a nickel-hydrogen storage battery by the method for producing a battery electrode of the present invention, wherein the electrode active material is a hydrogen storage alloy or an oxidation type hydrogen storage alloy. According to such a first aspect, an electrode in which a hydrogen storage alloy or an oxidized hydrogen storage alloy is firmly held by a conductive plating metal is manufactured. Therefore, in a nickel-hydrogen storage battery, it is possible to use a negative electrode having excellent conductivity and durability and having a sufficient electrode capacity.

A second aspect is a method for producing a negative electrode of a nickel-cadmium storage battery according to the method for producing a battery electrode of the present invention, wherein the electrode active material is cadmium. According to such a second aspect, an electrode in which cadmium is firmly held by a conductive plating metal is manufactured. Therefore, in a nickel-cadmium storage battery, it is possible to use a negative electrode having excellent conductivity and durability and having a sufficient electrode capacity.

A third aspect is a method for producing a positive electrode of a lithium battery by the method for producing a battery electrode according to the present invention. Here, as the positive electrode active material, LiCoO ₂ , LiNiO ₂ , L
If iMn ₂ O ₄ or the like is used, a positive electrode of a lithium secondary battery can be manufactured, and if manganese dioxide or fluorinated graphite is used as a positive electrode active material, a positive electrode of a lithium primary battery can be manufactured. In any case, an electrode in which a positive electrode active material is firmly held by a conductive plated metal is manufactured, and in a lithium battery, a positive electrode having excellent conductivity and durability and having sufficient electrode capacity can be used.

A fourth aspect is that in the method for producing a battery electrode according to the present invention, the fine particles containing the electrode active material have a substantially spherical shape, and the diameter thereof is 10 to 30 μm. According to such a fourth aspect, it becomes easy to form a uniform paste from the fine particles containing the electrode active material, and in the active material molded body obtained by drying this paste, the plating metal is deposited. Sufficient voids are formed between the electrode active materials, and sufficient conductivity is realized in the manufactured electrode.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION In order to further clarify the structure and operation of the present invention described above, the embodiments of the present invention will be described below based on Examples. First, a nickel-hydrogen storage battery using an electrode manufactured by the method for manufacturing a nickel electrode according to a preferred embodiment of the present invention will be described. Here, nickel oxyhydroxide or nickel hydroxide was used as the positive electrode active material, metal hydride or oxidized hydrogen storage alloy was used as the negative electrode active material, and 6M potassium hydroxide to which lithium hydroxide was added was used as the electrolytic solution. The reaction at the time of discharging in each electrode of such a nickel-hydrogen storage battery is as follows.

NiOOH + H ₂ O + e ⁻ → Ni (OH) ₂ + OH ⁻ (1) MH + OH ⁻ → M + H ₂ O + e ⁻ (2) NiOOH + MH → Ni (OH) ₂ + M (3)

The equation (1) represents the reaction on the positive electrode, the equation (2) the reaction on the negative electrode, and the equation (3) the reaction on the whole battery including the equations (1) and (2). Thus, when the battery is discharged, nickel oxyhydroxide, which is a positive electrode active material, changes to nickel hydroxide in the positive electrode, and the metal hydride is oxidized in the negative electrode. When the battery is charged, the opposite reaction to the above equation occurs.

Here, the structure of the nickel-hydrogen storage battery will be described. FIG. 2 is a cross-sectional view illustrating the configuration of a nickel-hydrogen storage battery that performs the above reaction. Here, the structure of the unit cell in which the separator 14 is arranged between the positive electrode 12 and the negative electrode 16 is shown. However, in actuality, a few dozen of these unit cells are stacked in series to form a unit as shown in FIG. It is assembled into a prismatic battery for use. In the positive electrode 12, a positive electrode operating portion 20 in which nickel oxyhydroxide as a positive electrode active material or nickel hydroxide and nickel as a conductive material are mixed at a predetermined ratio is arranged around a nickel foil 18 as a current collector. Has been done. In the negative electrode 16, a nickel foil 18 which is also a current collector
A negative electrode operating part 2 in which a hydrogen storage alloy as a negative electrode active material and nickel as a conductive material are mixed in a predetermined ratio around the
2 are arranged. Thus, by appropriately mixing the electrode active material and the conductive material in the operating part of each electrode,
Electrons involved in the above reaction occurring in the electrode active material are efficiently transmitted when the battery is operating, and electric energy generated by the electrons is taken out as a current during discharging. The manufacturing method of these electrodes corresponds to the main part of the present invention, and will be described in detail later. The separator 14 is
A non-woven fabric formed of a material stable to an electrolytic solution such as polypropylene or polyethylene is impregnated with the above-mentioned electrolytic solution to retain the electrolytic solution and to form the positive electrode 12 and the negative electrode 16
It also serves to separate the two poles by being placed between.

Next, a method of manufacturing the positive electrode of the above nickel-hydrogen storage battery will be described. FIG. 1 is a diagram illustrating a manufacturing process for manufacturing this positive electrode. First, a nickel foil (thickness 60 to 80 μm) as a current collector is prepared (step S100). Here, the nickel foil has a thickness of 6
0 μm and 100 mm × 100 mm were used.
Separately from this, a positive electrode active material paste is prepared (step S102). This is a process of adding 50 to 150 weight% of water to nickel hydroxide having a substantially spherical shape with a diameter of 10 to 50 μm to form a paste. Next, this positive electrode active material paste is applied to both surfaces of the nickel foil with a doctor knife (step S104). The positive electrode active material layer to be applied has a thickness of 100 to 500 μm. After applying the positive electrode active material paste, the nickel foil coated with this paste is dried (step S106). This drying step was performed at 80 to 200 ° C. for 5 to 120 minutes. As a result, water in the positive electrode active material paste evaporates, and an active material molded body in which particles of the positive electrode active material are lightly adhered to the nickel foil while being dispersed in the paste can be obtained.
The porosity of the active material molded body at this time is 20 to 100%. When the positive electrode active material paste is dried, the active material molded body is subjected to autocatalytic electroless plating (step S
108), a plating metal mainly containing nickel is deposited between the particles of the positive electrode active material (step S110) to complete the positive electrode.

FIG. 4 shows the positive electrode 1 manufactured by the above process.
2 is a partially enlarged schematic view of a part of 2. By applying the positive electrode active material paste and drying it, an active material forming body in which the positive electrode active material particles 24 are held around the nickel foil 18 in a state in which the positive electrode active material particles 24 are spaced apart according to the paste concentration is produced. By subjecting this active material forming body to a plating treatment, the positive electrode active material particles 2 are transferred from the surface of the nickel foil 18.
The plating metal layer 26 grows while filling the gap 4 to complete the positive electrode 12. In the positive electrode 12, the positive electrode active material particles 24 are firmly held by the plated metal layer 26.

Here, self-catalytic electroless plating will be described. The electroless plating is a plating method that does not require an electric circuit and does not receive electrons from the outside and can form a film by simply immersing an object to be plated in a plating solution.
Particularly, in self-catalytic electroless plating, the electrons received when the metal ions in the plating solution are reduced and deposited are also supplied from a reducing agent prepared in advance in the plating solution.
Furthermore, the surface of the object to be plated and the deposited metal itself are
Since it is catalytically active for the oxidizing reaction of this reducing agent, it is possible to obtain a film having an arbitrary thickness. As described above, in the plating solution, a salt that ionizes metal ions and a reducing agent that supplies electrons to the metal ions coexist and are thermodynamically unstable. And stabilizers are added. The complexing agent forms a stable soluble complex with metal ions in the plating solution and prevents the metal from depositing in the plating solution. The buffer is added to the p of the plating solution as the plating reaction progresses.
It suppresses the change of H and prevents the change of pH from affecting the reaction rate and the composition of the plated film. When a metal is deposited on a surface other than the surface of the object to be plated, the stabilizer adsorbs the metal to reduce the catalytic activity, and acts to selectively deposit a metal film only on the surface of the object to be plated. .

In this example, the active material molded body was plated with nickel-phosphorus alloy. The plating solution used was a solution containing nickel sulfate as a metal salt and sodium phosphinate as a reducing agent (MAC Nickel 600 manufactured by Okuno Chemical Co., Ltd.). When the above-mentioned active material molded body was dipped in such a plating solution, a nickel-phosphorus alloy containing about 3.5 to 4.0% of phosphorus started to precipitate from the surface of the current collector made of nickel foil. The alloy grows on the surface of the active material molded body so as to surround the particles while filling the gaps between the positive electrode active material particles in the active material molded body.

The above-described positive electrode manufacturing method has the following excellent effects, unlike the conventional method of packing the positive electrode active material in the fine holes provided in the conductor. That is, by filling the space between the particles of the positive electrode active material with a conductive nickel alloy, the conductivity of the electrode can be secured without adding a conductive agent. Moreover, since the positive electrode active material particles are held in the network of the plated metal, an electrode having excellent durability can be obtained. Further, since the positive electrode active material is evenly dispersed in the positive electrode active material paste, a nickel alloy can be deposited between the positive electrode active materials to obtain a positive electrode that uniformly contains the positive electrode active material. Therefore,
The reaction when the nickel-hydrogen alkaline storage battery using this positive electrode is operated is also carried out uniformly in the electrode. The operation for forming such a plating film is also a simple operation of immersing the active material molded body in the plating solution. Further, since the nickel foil is used as the current collector, the current collector itself is catalytically active for the oxidation reaction of the reducing agent, and it is not necessary to perform the catalyzing treatment of the current collector prior to the plating operation.

In the above electrode manufacturing method, the porosity of the active material molded body obtained by applying the paste to the current collector and drying it, and the basis weight of the plating applied to this active material molded body are completed. It greatly affects the performance of the electrode. That is, when the porosity of the active material molded body is low, the electrode capacity increases because the ratio of the amount of the electrode active material in the electrode increases, but the space where the plating metal precipitates decreases and the conductivity decreases and the durability decreases. It leads to deterioration of sex. If the basis weight of plating is large, the proportion of the conductive substance in the electrode is large, which leads to improved conductivity and durability, but the proportion of the electrode active material is small and the electrode capacity is reduced. . Therefore, it is necessary to maintain a proper balance between the two in order to realize good electrode performance. These conditions have different optimum values depending on the shape of the battery to be manufactured and the operating conditions, and therefore may be set appropriately within the allowable range in consideration of the ease of manufacturing work and cost. The results of examining these conditions are shown below.

FIG. 5 shows the results of comparing the performances of the finished electrodes by changing the conditions of the porosity of the active material molded body and the plating basis weight in the above electrode manufacturing method. Here, a nickel foil having a size of 100 × 100 mm and a thickness of 60 μm was coated with a paste in which the amount of water to be added was changed, and the paste was dried to prepare active material molded bodies having different porosities. The plating amount was changed and the performance of each finished electrode was compared. The porosity of the active material molded body can be adjusted by the amount of water added when preparing the electrode active material paste, and the porosity increases as the amount of water added increases. As a method of evaluating the electrode performance,
Sintered cadmium plates with a size of 100 × 100 × 0.8 mm were set on both sides of the electrode through a separator made of polyethylene non-woven fabric, and the electrode was placed in 6M potassium hydroxide.
Charged at 16mA for 20 hours, 50mA per gram of active material
The cycle of discharging to 0.8 V was repeated 5 times. Here, the average value of the measured discharge capacity (mAh) is used as the electrode capacity of each electrode, and the electrode capacity per electrode mass (g) of each electrode is used as the electrode capacity density (mAh / g) of each electrode. Were compared. No. 1 in FIG. 18 electrodes are
This is a nickel electrode manufactured by a conventional technique and prepared for comparison. In this electrode, an active material paste containing a conductive agent and a binder was rubbed into the fine pores of the nickel foam collector, which was dried and then pressed to form in the fine pores of the current collector. Bubbles are removed.

As shown in FIG. 1, 2, 3,
In the electrodes Nos. 6 and 16, the active material was lost during the above-mentioned charging / discharging cycle. Under these conditions, the coating weight is as small as 0.1 to 1%, so that the gap between the positive electrode active materials in the active material forming body is not sufficiently filled with the plating metal, and the positive electrode active material has a network of the plating metal. Is considered to be insufficiently retained.
In addition, No. 2 having a coating weight of 2%. With 8 electrodes,
Although no such lack of active material was observed, the electrode capacity density was inferior to that of the conventional electrode. Therefore, when the coating weight is 2%, the durability is sufficient to keep the active material during the charging / discharging cycle, but the network of the plating metal is still insufficient and the conductivity of the electrode cannot be sufficiently achieved. I can say.

No. The electrodes 15 and 17 also have inferior electrode capacitance densities to the electrodes of the prior art. Under these conditions, the coating weight is 50%, the positive electrode active material is firmly held by the deposited plating metal, and the conductivity of the electrode is sufficient. However, in this case, it is considered that the electrode mass increased due to an excessive increase in the amount of plated metal, resulting in a decrease in the electrode capacitance density.

From the above results, the positive electrode active material is sufficiently retained, the durability as an electrode is secured, sufficient conductivity is realized, and the electrode capacity density is not lowered due to the increase of the electrode mass. As for the range, the coating weight is
It can be said that 5 to 20% is good. Regarding the porosity of the active material molded body, if the porosity is too small, the gap between the positive electrode active materials becomes small, so that it becomes difficult to deposit the plated metal within the above range. Further, if the porosity is too large, the gap between the positive electrode active materials becomes large, so that with the basis weight of the above range, the gap between the positive electrode active materials cannot be sufficiently filled, resulting in poor conductivity, and conversely If the basis weight is increased to secure the conductivity, the electrode mass increases and the electrode capacitance density decreases. Therefore, the porosity of the active material molded body is considered to be 20 to 100%. The porosity of this active material molded body can be adjusted by the amount of water added when the positive electrode active material is made into a paste, but in order to obtain an active material molded body having a porosity within the above range, 150 wt% of water may be added to the positive electrode active material to form a paste.

In the above-mentioned examples, since the current collector used in the production of the positive electrode was the nickel foil, the current collector itself was catalytically active for the oxidation reaction of the reducing agent in the plating solution during electroless plating. Had. Therefore, it was possible to apply the paste as it is to the current collector and use it for electroless plating. However, it suffices that the material used as the current collector has conductivity, and even if a material requiring pretreatment or a material having almost no catalytic activity, such as an iron foil or a copper foil, a suitable front It can be similarly used as a current collector by subjecting it to a treatment and subjecting the surface to electro-nickel plating for a short time. After the pretreatment and the catalyzation treatment, a paste may be similarly applied and electroless plating may be performed. Therefore, the material used as the current collector may be electrically conductive and stable under the conditions (temperature, electrode potential, etc.) when the battery operates. As a form of the current collector, a thin foil is sufficient for applying the paste, and a foil is preferable for thinning the battery. However, it may have a predetermined thickness depending on the form of the battery to be manufactured.

It is necessary that the positive electrode active material is uniformly paste-formed when water is added, and can form appropriate voids when the active material molded body is formed.
It is preferably spherical form having a diameter of μm,
Different shapes may be used as long as the above conditions are satisfied. Further, in order to form a uniform paste, it is preferable that the particles and the size of the positive electrode active material are uniform. In this example, when the paste to be applied to the current collector was prepared, the proportion of the positive electrode active material in the electrode was increased by using the fine particles composed of only the positive electrode active material, and the electrode capacity was increased. If the capacity is within the allowable range, fine particles of a conductive agent or a binder may be added during paste preparation. By adding a conductive agent, the conductivity of the electrode can be adjusted, and by adding a binder, the durability of the active material molded body before plating can be improved.

Further, in the above embodiment, the active material molded body was plated with nickel-phosphorus alloy using phosphinate as a reducing agent, but it contains boron such as sodium tetrahydroborate or dimethylamine borane. Nickel-boron alloy plating may be applied using a reducing agent. Also in this case, just as in the case of nickel-phosphorus alloy plating, simply immersing the active material molded body in a predetermined plating solution,
A very uniform plating film can be formed in any thickness. Alternatively, the active material molded body may be connected to the negative electrode and the nickel metal may be connected to the positive electrode to form an electric circuit, and electroplating may be performed to deposit nickel metal between the positive electrode active materials. In this case, the composition of the plating solution is simple, bath management of the plating solution is easy, and plating can be easily performed at a lower cost.

Further, in the above-mentioned embodiment, the cells formed of the electrodes and the separators are stacked and the prismatic battery shown in FIG. 3A is assembled. However, the manufactured electrodes and the separator are stacked in layers. Alternatively, the battery may be rounded to form a cylindrical battery shown in FIG. Further, the battery can be downsized to a dry battery type.

Although the positive electrode of the nickel-hydrogen storage battery is manufactured by the electrode manufacturing method of the present invention in the above-mentioned embodiment, the negative electrode of the nickel-hydrogen storage battery can be manufactured by the electrode manufacturing method of the present invention. In this case, using the same current collector as in the production of the positive electrode described above, a paste was prepared by mixing an appropriate amount of platinum, which is a catalyst for hydrogen ionization, with a hydrogen storage alloy, which is the negative electrode active material. Is coated on a current collector and dried to form an active material forming body, which is dipped in a plating solution and subjected to autocatalytic electroless plating or electroplating as in the case of the positive electrode.

Further, in the above embodiment, the manufactured nickel electrode is used as the positive electrode of the nickel-hydrogen storage battery, but this nickel electrode is also used as the positive electrode of the nickel-cadmium storage battery which is also an alkaline storage battery. You can also

Further, according to the electrode manufacturing method of the present invention,
It is also possible to manufacture the negative electrode of a nickel-cadmium storage battery. In this case, using the same current collector as in the production of the positive electrode described above, a paste of cadmium, which is the negative electrode active material, was prepared, and the paste was applied to the current collector and dried to form an active material forming body. It may be immersed in a liquid and subjected to autocatalytic electroless plating or electroplating as in the case of the positive electrode.

The electrode manufacturing method of the present invention can also be applied to manufacturing the positive electrode of a lithium secondary battery. In this case, the same current collector as that used for producing the nickel electrode is used, and an electrode is similarly produced using LiCoO ₂ , LiNiO ₂ , LiMn ₂ O _4, etc. as the positive electrode active material. Furthermore, the electrode manufacturing method of the present invention can also be applied to manufacturing a positive electrode of a lithium primary battery. In this case, a paste is prepared using manganese dioxide or fluorinated graphite as the positive electrode active material. In any case, the positive electrode active material paste may be applied to a current collector similar to that in the above-described embodiment, dried, and then the finished active material-formed body may be plated.

The embodiment of the present invention has been described above.
It is needless to say that the present invention is not limited to these embodiments and can be implemented in various modes without departing from the scope of the present invention. The electrode manufacturing method of the present invention can be applied to various electrodes when the active material of the electrode is solid and has no conductivity, and particularly in the case of a secondary battery, it is associated with the operation of the battery. In a battery in which no deformation such as dissolution or precipitation of the electrode active material is observed, durability and long cycle life can be realized. When the electrode active material becomes a catalyst poison in electrocatalytic electroless plating, electroplating may be performed as the plating treatment, and the electrode manufacturing method of the present invention can be applied to a wide range.

[Brief description of the drawings]

FIG. 1 is an explanatory view illustrating a manufacturing process of a nickel electrode which is a preferred embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating the configuration of a nickel-hydrogen storage battery using an electrode manufactured by a method for manufacturing a nickel electrode according to an example.

FIG. 3 is an explanatory view illustrating the form of a battery assembled by using the electrode manufactured by the method for manufacturing the nickel electrode of the example.

FIG. 4 is an explanatory view schematically showing the structure of an electrode manufactured by the method for manufacturing a nickel electrode of the example.

FIG. 5 is an explanatory diagram illustrating the results of studying the influence of the porosity of the active material forming body and the plating basis weight on the electrode performance in the method for manufacturing the nickel electrode of the example.

[Explanation of symbols]

 12 ... Positive electrode 14 ... Separator 16 ... Negative electrode 18 ... Nickel foil 20 ... Positive electrode working part 22 ... Negative working part 24 ... Positive electrode active material particles 26 ... Plating metal layer

Claims (7)

[Claims] 1. A conductive current collector is arranged at the base, and a paste prepared by kneading fine particles containing an electrode active material with a predetermined liquid is applied to the periphery of the current collector, and the paste is dried to obtain the paste. A predetermined liquid is evaporated, fine particles containing the electrode active material are spaced from each other by predetermined gaps to prepare an active material molded body which is held around the current collector, and the active material molded body is plated. A method for producing an electrode for a battery, which comprises carrying out deposition of a conductive plating metal between fine particles containing the electrode active material in the molded active material. 2. The method for producing a battery electrode according to claim 1, wherein the plating applied to the active material molded body is electrocatalytic electroless plating. 3. The method for producing a battery electrode according to claim 2, wherein the current collector is made of a metal having catalytic activity in electroless plating. 4. The predetermined liquid used for forming the fine particles containing the electrode active material into a paste is water.
A method for producing the battery electrode described. 5. The method for manufacturing a battery electrode according to claim 1, wherein the current collector is made of nickel, and the electrode active material is nickel oxyhydroxide and / or nickel hydroxide. A method for manufacturing a battery electrode, wherein the plating applied to the active material molded body is nickel plating. 6. An electrode comprising a conductive current collector disposed on a base, and forming an electrode operating portion around the current collector in which an electrode active material and a conductive material are mixed in a predetermined ratio. The electrode operating unit is an electrode in which the electrode active material dispersed at a predetermined interval is held by a conductive plating metal deposited between the electrode active materials. 7. The electrode according to claim 6, wherein the current collector is made of nickel, the electrode active material is nickel oxyhydroxide and / or nickel hydroxide, and is deposited between the electrode active materials. Electrodes whose conductive plating metal is nickel.