JP2003168473A - Cylinder type storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder type storage battery, which suppresses capacity degradation by the electricity charging/discharging cycle and improves the cycle characteristic. <P>SOLUTION: Concerning the cylinder type storage battery 100, which uses beta type nickel oxy-hydroxide as a positive-electrode active material, has positive electrode mix 3 molded in a shape of a hollow cylinder, and has negative electrode mix 5, which makes zinc the main negative electrode active material in the central part of the battery through a cylindrical type separator 4 that has a bottom, a metal cylinder 12 that has a hole is provided between the positive electrode mix 3 and the separator 4. This metal cylinder 12 that has the hole is what has for example the thickness of 50 to 200 μm. Moreover, the metal cylinder 12 that has the hole is formed for example, with either a punching metal made from hollow cylinder-like stainless steel, a metal net or an expanded metal. By this, the moisture generated in the positive electrode at the time of charge is pushed out from the separator to the negative electrode, the expansion of the positive electrode is suppressed, and movement of the moisture between the positive electrode and the negative electrode becomes good at the time of the electricity charging/discharging. Then, it becomes possible to obtain the cylindrical type storage battery, which is improved in the cycle characteristic. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cylindrical storage battery. Specifically, it consists of a hollow cylindrical positive electrode and a negative electrode arranged in the hollow portion of the positive electrode via a bottomed cylindrical separator, or a hollow negative electrode via a hollow cylindrical negative electrode and a bottomed cylindrical separator. By providing a perforated cylindrical metal having a predetermined thickness between the positive electrode and the separator of the cylindrical storage battery composed of the positive electrode arranged in the part, the expansion of the positive electrode due to the water generated in the positive electrode during charging is suppressed, Thus, the present invention relates to a cylindrical storage battery in which water generated in the positive electrode is efficiently moved to the negative electrode, capacity deterioration due to charge / discharge cycles is suppressed, and cycle characteristics are improved.

[0002]

2. Description of the Related Art With the recent popularization of portable electronic devices, the demand for cylindrical alkaline batteries is ever increasing. In addition, since portable electronic devices, which used to have a high drive voltage, are gradually becoming lower in voltage, low-voltage secondary batteries will take an extremely important position. On the other hand, the environmental load can be reduced by converting the primary battery into a secondary battery and repeatedly using it.

Conventionally, there are a nickel hydrogen battery and a nickel cadmium battery as a battery using nickel as a positive electrode active material. In both of these, the nickel positive electrode is mainly used as nickel hydroxide. First of all, there is a drawback that it needs to be charged and cannot be used immediately after being manufactured.

On the other hand, an alkaline storage battery using manganese dioxide as a positive electrode active material and zinc as a negative electrode active material has been proposed as a battery that does not require initial charging. However, manganese dioxide has a poor reversibility in a charge / discharge cycle, and is difficult to return to the initial manganese dioxide even after being charged after being discharged, so that the capacity rapidly deteriorates when the charge / discharge cycle is repeated.
Therefore, low-cost nickel-zinc storage batteries with high energy density that do not require initial charging have attracted attention.

FIG. 6 shows the structure of a conventional inside-out type nickel-zinc storage battery. The nickel-zinc storage battery 1 includes a battery can 2, a positive electrode mixture 3, and a separator 4.
The negative electrode mixture 5, the current collecting pin 6, the gasket 7, the neutral cover 8, and the negative electrode terminal 9. The battery can 2 is formed by pressing a metal plate plated with nickel, for example. This battery can 2
Also serves as the positive electrode terminal of the nickel-zinc storage battery 1.

[0006] The positive electrode mixture 3 has a hollow cylindrical shape and is arranged inside the battery can 2. The positive electrode mixture 3 is formed by mixing beta-type nickel oxyhydroxide as a positive electrode active material, carbon powder as a conductive agent, and an alkaline aqueous solution as an electrolytic solution, and molding the mixture into a hollow cylindrical shape. Graphite powder is used as the carbon powder used as the conductive agent. As the alkaline aqueous solution, for example, an aqueous potassium hydroxide solution is used, but an aqueous solution of lithium hydroxide, sodium hydroxide or the like or a mixture thereof can also be used.

The positive electrode mixture 3 is manufactured as follows. First, beta-type nickel oxyhydroxide, graphite powder, and 40% KOH potassium hydroxide aqueous solution in a weight ratio of 1
Weigh in a ratio of 0: 1: 1 and mix by a stirring method such as an impeller or a ball mill. Next, the mixed material is pressure-molded into a hollow cylinder to obtain the positive electrode mixture 3.

The separator 4 has a cylindrical shape with a bottom,
It is arranged inside the positive electrode mixture 3. For example, as the separator 4, a non-woven fabric of synthetic fibers having good liquid absorption and liquid retention properties and excellent alkali resistance is used.

The negative electrode mixture 5 is in the form of gel and is filled in the separator 4. This negative electrode mixture 5 is obtained by uniformly dispersing and mixing granular zinc and zinc oxide, which are negative electrode active materials, in an aqueous solution of potassium hydroxide, which is an electrolytic solution, using a gelling agent.

The opening of the battery can 2 is sealed by an insulating gasket 7, a neutral cover 8 and a negative electrode terminal 9. A metal collector pin 6 is welded to the negative electrode terminal 9.

The nickel-zinc storage battery 1 shown in FIG. 6 is manufactured as follows. First, the positive electrode mixture 3 pressure-molded into a hollow cylinder is inserted into the battery can 2. Next, the bottomed cylindrical separator 4 is inserted into the center of the positive electrode mixture 3,
A gelled negative electrode mixture 5 is filled in the separator 4.
Finally, the insulator gasket 7, the neutral cover 8 and the negative electrode terminal 9 are inserted into the battery can 2, and the edge of the opening of the battery can 2 is bent inside to fix the gasket 7.
When inserting the gasket 7 or the like into the battery can 2, the collector pin 6 welded to the negative electrode terminal 9 is inserted into the gelled negative electrode mixture 5.

In the nickel-zinc storage battery 1 shown in FIG. 6, the current collection of the negative electrode is carried out by collecting the current collecting pin 6 welded to the negative electrode terminal 9.
Is ensured by being inserted into the negative electrode mixture 5. Further, the current collection of the positive electrode is ensured by connecting the positive electrode mixture 3 and the battery can 2. The outer peripheral surface of the battery can 2 is
It is covered with the outer label 10, and the positive electrode terminal 11 is located on the convex portion (the upper portion of the illustrated nickel-zinc storage battery 1) on the bottom of the battery can 2.

The charging / discharging reaction of this nickel-zinc storage battery is repeated charging and discharging according to the following equation. Discharge reaction Positive electrode NiOOH + H ₂ O + e ⁻ → Ni (OH) ₂ + OH ⁻ (1) Negative electrode Zn + 2OH ⁻ → ZnO + H ₂ O + 2e ⁻ (2) Overall 2NiOOH + H ₂ O + Zn → 2Ni (OH) ₂ + ZnO (3) Charge reaction Positive electrode Ni (OH) ₂ + OH ⁻ → NiOOH + H ₂ O + e ⁻ (4) Negative electrode ZnO + H ₂ O + 2e ⁻ → Zn + 2OH ⁻ (5) Overall 2Ni (OH) ₂ + ZnO → 2NiOOH + H ₂ O + Zn (6)

As described above, during discharge, the water content of the positive electrode disappears according to the formula (1), and the water content that is not sufficient during the discharge is impregnated in the separator, the water content contained in the negative electrode, or the water content generated according to the formula (2). Is used to proceed the discharge reaction. Even when the battery as a whole is discharged, the water content decreases according to the equation (3). On the contrary, at the time of charging, the water generated in the positive electrode moves to the negative electrode according to the formula (4), and the charging reaction proceeds in the negative electrode according to the formula (5). When the battery as a whole is charged, the water content increases according to the equation (6) and returns to the initial state.

[0015]

As described above, the inside-out type nickel-zinc storage battery 1 has a large discharge capacity, but it discharges when the cycle is repeated like an alkaline storage battery using manganese dioxide as the positive electrode active material. There is a problem that the capacity is significantly reduced and the cycle characteristics are poor.

The following can be considered as one of the causes. That is, during the charging / discharging cycle, particularly during the discharging period, the volume of the positive electrode portion increases due to the chemical change of the positive electrode active material, so that part of the water generated in the positive electrode is stored in the positive electrode during charging. As a result, the positive electrode gradually expands, and a part of the water that has moved to the positive electrode during discharging does not return to the negative electrode. As a result, the water content of the positive electrode becomes excessive and the water content of the negative electrode becomes insufficient, so that the positive electrode and the negative electrode do not return to the initial state even after charging. Therefore, when the charge / discharge cycle is repeated, the discharge capacity decreases and the cycle characteristics deteriorate.

Therefore, according to the present invention, the expansion of the positive electrode due to the moisture generated in the positive electrode during charging is suppressed, the moisture generated in the positive electrode is efficiently moved to the negative electrode, and the capacity deterioration due to the charge / discharge cycle is suppressed. An object is to provide a cylindrical storage battery with improved characteristics.

[0018]

A cylindrical storage battery according to the present invention is filled in a hollow portion of a positive electrode through a positive electrode made of a positive electrode mixture formed in a hollow cylindrical shape and a bottomed cylindrical separator. In a cylindrical storage battery having a negative electrode composed of a negative electrode mixture, a perforated metal cylinder having a predetermined thickness is provided between the positive electrode and the separator.

The cylindrical storage battery according to the present invention comprises a negative electrode made of a negative electrode mixture formed in a hollow cylindrical shape, and a positive electrode mixture filled in the hollow portion of the negative electrode via a bottomed cylindrical separator. In a cylindrical storage battery having a negative electrode
A perforated metal cylinder having a predetermined thickness is provided between the positive electrode and the separator.

In the present invention, a hollow cylindrical positive electrode and a negative electrode arranged in the hollow portion of the positive electrode via a bottomed cylindrical separator, or a hollow cylindrical negative electrode and a bottomed cylindrical separator are used. And a positive electrode disposed in the hollow part of the negative electrode via a metal cylinder having a hole between the positive electrode and the separator. The perforated metal cylinder has, for example, a thickness of 50 to 200 μm. The perforated metal cylinder is formed of, for example, a hollow cylindrical stainless steel, nickel, copper or tin punching metal, a metal net or an expanded metal. As a result, the water generated in the positive electrode during charging is pushed out to the negative electrode, the expansion of the positive electrode due to this water is suppressed, the water generated in the positive electrode during charging is efficiently transferred to the negative electrode, and capacity deterioration due to charge / discharge cycles is suppressed. It becomes possible to obtain a cylindrical storage battery with improved cycle characteristics.

In this case, the perforated metal cylinder functions to suppress the expansion of the positive electrode during the charging process and to push out the water generated in the positive electrode during charging to the negative electrode, thus keeping the positive electrode in the initial state. Further, in the next discharge process, water can be supplied from the negative electrode to the positive electrode. The capacity deterioration due to charge / discharge cycles depends on the thickness of the perforated metal cylinder.
When the thickness is less than 0 μm, the positive electrode active material expands similarly to the case without the perforated metal cylinder. Further, when the thickness is thicker than 200 μm, the distance between the positive electrode mixture and the separator becomes long, so that it becomes difficult to efficiently move water from the positive electrode to the negative electrode.

Further, at least one element selected from Zn, Co and Mg may be solid-dissolved in beta-type nickel oxyhydroxide which is a positive electrode active material. These elements have the effect of suppressing the expansion of the positive electrode active material itself,
It is possible to suppress capacity deterioration due to charge / discharge cycles. The amount of these elements is preferably about 0.1 to 20 wt% (wt%) with respect to the amount of nickel in nickel oxyhydroxide. If the amount of element is less than this, the effect of suppressing the expansion of the positive electrode active material during charging cannot be sufficiently exerted, and if the amount of element is more than this, the amount of beta-type nickel oxyhydroxide as the positive electrode active material decreases. Therefore, the discharge capacity is reduced.

Taking the solid solution amount of zinc as an example, the solid solution amount is represented by the zinc solid solution rate, and the zinc solid solution rate (wt%) = {(zinc amount) / (nickel amount + zinc amount)} × 100 Is expressed as

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below. FIG. 1 shows the configuration of a cylindrical storage battery 100 according to the first embodiment. The cylindrical storage battery 100 is an AA nickel-zinc storage battery having an inside-out structure. Further, in FIG. 1, parts corresponding to those in FIG. 6 are denoted by the same reference numerals.

This cylindrical storage battery 100 includes a battery can 2 and
It is composed of a positive electrode mixture 3, a separator 4, a negative electrode mixture 5, a current collecting pin 6, a gasket 7, a neutral cover 8, a negative electrode terminal 9, and a perforated metal cylinder 12.
The battery can 2 is formed by pressing a metal plate plated with nickel, for example. The battery can 2 also serves as the positive electrode terminal of the cylindrical storage battery 100.

The positive electrode mixture 3 has a hollow cylindrical shape and is arranged inside the battery can 2. The positive electrode mixture 3 is formed by mixing beta-type nickel oxyhydroxide as a positive electrode active material, carbon powder as a conductive agent, and an alkaline aqueous solution as an electrolytic solution, and molding the mixture into a hollow cylindrical shape. Graphite powder is used as the carbon powder used as the conductive agent. As the alkaline aqueous solution, for example, an aqueous potassium hydroxide solution is used, but an aqueous solution of lithium hydroxide, sodium hydroxide or the like or a mixture thereof can also be used.

The positive electrode mixture 3 is manufactured as follows. First, beta-type nickel oxyhydroxide, graphite powder, and an aqueous potassium hydroxide (KOH) solution having a concentration of 40% are weighed at a weight ratio of 10: 1: 1 and mixed by a stirring method such as an impeller or a ball mill. Next, the mixed material is pressure-molded into a hollow cylinder to obtain the positive electrode mixture 3.

The separator 4 has a cylindrical shape with a bottom,
It is arranged inside the positive electrode mixture 3. For example, as the separator 4, a non-woven fabric of synthetic fibers having good liquid absorption and liquid retention properties and excellent alkali resistance is used.

The negative electrode mixture 5 is in the form of gel and is filled in the separator 4. This negative electrode mixture 5 is obtained by uniformly dispersing and mixing granular zinc and zinc oxide, which are negative electrode active materials, in an aqueous solution of potassium hydroxide, which is an electrolytic solution, using a gelling agent.

The perforated metal cylinder 12 is arranged between the positive electrode mixture 3 and the separator 4, and is made of a metal such as stainless steel, nickel, copper, tin, or the like, a metal net, an expanded metal, or the like.

Further, since the metal that can be used as the perforated metal cylinder depends on the type of the electrolytic solution of the storage battery and the types of the positive electrode and the negative electrode, the metal that can be used will differ if the battery system changes.
For example, in the case of a nickel-zinc storage battery, a metal such as stainless steel, nickel, copper or tin that does not react with an alkaline aqueous solution or a positive electrode can be used.

The opening of the battery can 2 is sealed by an insulating gasket 7, a neutral cover 8 and a negative electrode terminal 9. A metal collector pin 6 is welded to the negative electrode terminal 9.

The cylindrical storage battery 100 shown in FIG. 1 is manufactured as follows. First, the positive electrode mixture 3 pressure-molded into a hollow cylinder is inserted into the battery can 2. Next, the perforated metal cylinder 12 is placed inside the positive electrode mixture formed into a hollow cylinder.
Insert. Next, the bottomed cylindrical separator 4 is inserted inside the perforated metal cylinder 12, and the separator 4 is filled with the gelled negative electrode mixture 5. Finally, the insulator gasket 7, the neutral cover 8 and the negative electrode terminal 9 are inserted into the battery can 2, and the edge of the opening of the battery can 2 is bent inside to fix the gasket 7. Gasket 7 on battery can 2
Collector pin 6 welded to the negative electrode terminal 9 when inserting the etc.
Is inserted into the gelled negative electrode mixture 5.

In the cylindrical storage battery 100 shown in FIG. 1, the current collection of the negative electrode is ensured by inserting the current collection pin 6 welded to the negative electrode terminal 9 into the negative electrode mixture 5.
Further, the current collection of the positive electrode is ensured by connecting the positive electrode mixture 3 and the battery can 2. The outer peripheral surface of the battery can 2 is covered with an outer label 10 on which the manufacturer name, battery type, cautionary notes, etc. are written, and the convex portion on the bottom of the battery can 2 (the upper part of the illustrated cylindrical storage battery 100). The positive terminal 11
Is located. The charging / discharging reaction in the cylindrical storage battery 100 is performed according to the above equations (1) to (6).

Here, beta-type nickel oxyhydroxide as the positive electrode active material in the present embodiment will be further described. This beta-type nickel oxyhydroxide is produced by chemically oxidizing nickel hydroxide. For example, this beta-type nickel oxyhydroxide is prepared by combining nickel hydroxide with a suitable oxidizing agent such as sodium hypochlorite (NaClO) and a suitable alkaline species such as lithium hydroxide, sodium hydroxide, potassium hydroxide. It can be obtained by oxidation in a liquid phase containing The oxidation reaction at this time is as follows. 2Ni (OH) ₂ + ClO ⁻ → 2NiOOH + Cl ⁻
+ H ₂ O

By thus producing beta-type nickel oxyhydroxide by chemical oxidation, in the process,
Impurity ions such as NO ₃ ⁻ and CO ₃ ²⁻ flow out into the liquid phase and are removed from the crystal to some extent. As a result, beta-type nickel oxyhydroxide having less self-discharge and more suitable as an active material for batteries can be obtained. Incidentally, the self-discharge of nickel oxyhydroxide is caused by the N contained in the crystal.
It is considered that impurity ions such as O ₃ ⁻ and CO ₃ ²⁻ are decomposed and generated in the battery.

The crystal structure of the nickel oxyhydroxide produced differs depending on the pH in the liquid phase. Ie pH
Below a certain value, a high density of beta-type nickel oxyhydroxide (theoretical density: 4.68 g / cm ³ ) is produced, while at a value higher than that, a low-density gamma-type nickel oxyhydroxide (theoretical density: 3.79 g / cm ³ ) is produced.

At this time, as the starting material, nickel hydroxide used is a high density nickel hydroxide having spherical particles. Thereby, the beta-type nickel oxyhydroxide, which is the positive electrode active material in the present embodiment, has a spherical particle shape. Here, the term “spherical” is a concept including a state in which the shape is nearly spherical. The same applies to the following.

The above-mentioned beta-type nickel oxyhydroxide is
It contains at least one selected from Zn, Co and Mg in a solid solution state. Solid solution components such as Zn, Co, and Mg are solid-dissolved with nickel hydroxide during the production of nickel hydroxide. Generally, nickel hydroxide is prepared by dissolving a nickel salt such as nickel sulfate or nickel nitrate in water to prepare a nickel salt aqueous solution having a predetermined concentration, and then adding an alkaline aqueous solution such as a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution. After mixing to generate insoluble nickel hydroxide by a neutralization reaction, the nickel hydroxide is washed with water to remove unnecessary by-product salts, and then dried. At this time, nickel hydroxide in which at least one selected from Zn, Co, and Mg is solid-solved can be obtained by previously dissolving a salt such as zinc sulfate together with a nickel salt in water.

The cylindrical storage battery 100 shown in FIG. 1 was evaluated for cycle characteristics by measuring the discharge capacity under the following test conditions. In the charge and discharge test, 10 batteries for each example were discharged at a current of 100 mA until the voltage reached 1 V, and then charged until the voltage reached 1.9 V, which was defined as one cycle, and the capacity was maintained after 50 cycles. The rates were compared.

The capacity maintenance ratio is a ratio (%) to the initial discharge capacity and is expressed by the following equation. 50th cycle capacity retention ratio (%) = {(50th cycle discharge capacity) / (first time discharge capacity)} × 100

Here, the following Comparative Example 1 and Examples 1 and 2 are used.
The cylindrical storage battery 100 of No. 1 was examined. Comparative Example 1 has the same specifications as the conventional nickel-zinc storage battery 1, and the positive electrode mixture 3
Beta-type nickel oxyhydroxide used in the above is manufactured by the chemical oxidation method, and the shape of the particles is spherical.
A solid solution of at least one selected from n, Co, and Mg was used. The positive electrode mixture 3 is beta-type nickel oxyhydroxide: graphite powder: 40% KOH electrolytic solution 10: 1:
It was mixed at a ratio of 1. 10 g of the positive electrode mixture 3 was used and molded in the positive electrode can 2 into a hollow cylinder having an outer diameter of 13.3 mm, an inner diameter of 9.0 mm, and a height of 40 mm. Insert a separator with a thickness of 0.2 mm here, inject 1.5 g of electrolytic solution, and then add to the mixture of zinc powder, gelling agent and 40% KOH electrolytic solution in the ratio of 65: 1: 34. A negative electrode mixture prepared by adding a small amount of the agent was filled in an amount of 5 g, and a battery was produced according to the above-described nickel zinc storage battery 1 producing procedure.

In Examples 1 to 6, beta-type nickel oxyhydroxide used for the positive electrode mixture 3 was manufactured by a chemical oxidation method, and the shape of the particles was spherical.
The solid solution of at least one selected from the above was used. The positive electrode mixture 3 is a mixture of beta-type nickel oxyhydroxide: graphite powder: 40% KOH electrolyte at a ratio of 10: 1: 1. 10 g of the positive electrode mixture 3 was used and molded in the positive electrode can 2 into a hollow cylinder having an outer diameter of 13.3 mm, an inner diameter of 9.0 mm, and a height of 40 mm. Next, inside the positive electrode mixture molded into a hollow cylinder, the outer diameter was 9.0 mm and the height was 4 mm.
Thickness of 30 mm, 50 mm, and 10 mm processed into a hollow cylinder
0, 150, 200, 250 μm stainless steel punching metal was inserted respectively, a 0.2 mm thick separator was inserted therein, and 1.5 g of electrolytic solution was injected, followed by zinc powder, gelling agent, 40% 65: 1: 34 KOH electrolyte
5 g of a negative electrode mixture prepared by adding a small amount of an additive to a mixture mixed at a ratio of
Each battery was manufactured according to the manufacturing procedure of. Table 1 shows the results obtained by measuring Comparative Example 1 and Examples 1 to 6 under the above-described test conditions.

[0044]

[Table 1]

In Examples 7 to 12, thicknesses 30, 50, and 10 of a hollow cylinder having an outer diameter of 9.0 mm and a height of 40 mm were formed between the positive electrode mixture and the separator, which were formed into a hollow cylinder shape.
Metallic nets made of stainless steel of 0, 150, 200, and 250 μm were arranged, respectively. Other than that, batteries were manufactured in the same manner as in Examples 1 to 6 according to the manufacturing procedure of the cylindrical storage battery 100 described above. Table 2 shows the results of measuring these Examples 7 to 12 under the above-mentioned test conditions. Comparative Example 1 in Table 2 is as described above.

[0046]

[Table 2]

In Examples 13 to 18, thicknesses 30, 50, 1 processed into a hollow cylindrical shape having an outer diameter of 9.0 mm and a height of 40 mm were provided between the positive electrode material mixture molded in the hollow cylindrical shape and the separator.
00, 150, 200, and 250 μm expanded metal made of stainless steel were arranged, respectively. Other than that, batteries were manufactured in the same manner as in Examples 1 to 6 according to the manufacturing procedure of the cylindrical storage battery 100 described above. Example 1
Table 3 shows the results of measuring 3 to 18 under the above-mentioned test conditions. Comparative Example 1 in Table 3 is as described above.

[0048]

[Table 3]

From the measurement results of Tables 1 to 3, the relationship curve between the thickness of the perforated metal cylinder 12 and the capacity retention ratio of FIG. 2 can be obtained. According to FIG. 2, after 50 cycles, the cylindrical storage battery 100
The thickness of the perforated metal cylinder 12 is 5
It is in the range of 0 to 200 μm. Among them, the thickness is 100
In the case of 150 μm, a higher capacity retention rate can be obtained.
That is, the capacity deterioration due to the charge / discharge cycle is caused by the perforated metal cylinder 12
If the thickness is less than 50 μm, for example, the positive electrode active material expands as in the case without the perforated metal cylinder 12. Further, when the thickness is thicker than 200 μm, the distance between the positive electrode mixture 3 and the separator 4 becomes long, so that it becomes difficult to efficiently move water from the positive electrode to the negative electrode. Therefore, by setting the thickness of the perforated metal cylinder 12 in the range of 50 to 200 μm, the expansion of the positive electrode due to the moisture generated in the positive electrode during charging is suppressed, and the moisture generated in the positive electrode during charging is efficiently discharged. It is possible to obtain a cylindrical storage battery that is well moved to the negative electrode and has improved cycle characteristics.

Next, the cylindrical storage batteries 100 of Examples 19 to 21 in which the materials of the perforated metal cylinder 12 were different were examined. Example 19 is a positive electrode mixture 3 formed in a hollow cylindrical shape.
As a perforated metal cylinder 12, a 100 mm thick punching metal made of nickel processed into a hollow cylinder having an outer diameter of 9.0 mm and a height of 40 mm was disposed between the separator 4 and the separator 4.
A battery was manufactured according to the procedure for manufacturing the cylindrical storage battery 100 described above with the same specifications as in Examples 1 to 6 except for the above.

In Example 20, between the positive electrode mixture 3 and the separator 4, which were formed into a hollow cylinder shape, the perforated metal cylinder 12 was processed into a hollow cylinder shape having an outer diameter of 9.0 mm and a height of 40 mm. A copper punching metal having a thickness of 100 μm was arranged. A battery was manufactured according to the procedure for manufacturing the cylindrical storage battery 100 described above with the same specifications as in Examples 1 to 6 except for the above.

In Example 21, between the positive electrode mixture 3 and the separator 4, which were formed into a hollow cylindrical shape, the perforated metal cylinder 12 was processed into a hollow cylindrical shape having an outer diameter of 9.0 mm and a height of 40 mm. A punching metal made of tin having a thickness of 100 μm was arranged. A battery was manufactured according to the procedure for manufacturing the cylindrical storage battery 100 described above with the same specifications as in Examples 1 to 6 except for the above. Table 4 shows the results of measuring these Examples 19 to 21 under the above-mentioned test conditions. Comparative Example 1 in Table 4 is as described above.

[0053]

[Table 4]

From the measurement results of Table 4 and the above-mentioned Example 3, the relationship between the metal type and the capacity retention rate of the perforated metal cylinder 12 of FIG. 3 can be obtained. It is clear from FIG. 3 that the capacity retention ratio was higher than that of Comparative Example 1 for each type of metal. Above all, in the case of nickel punching metal and stainless punching metal, a higher capacity retention rate can be obtained.

In this way, the positive electrode made of the positive electrode mixture 3 formed in the hollow cylindrical shape and the negative electrode made of the negative electrode mixture 5 filled in the hollow portion of the positive electrode via the bottomed cylindrical separator 4 are provided. In the cylindrical storage battery having, a perforated metal cylinder 12 such as a punching metal made of stainless steel, nickel, copper or tin, a metal net or an expanded metal is provided between the positive electrode mixture 3 and the separator 4, and the perforated metal cylinder 12
The thickness of 50 to 200 μm, the expansion of the positive electrode due to the moisture generated in the positive electrode during charging is suppressed, whereby the moisture generated in the positive electrode is efficiently transferred to the negative electrode, and the capacity due to the charge / discharge cycle is increased. It is possible to obtain a cylindrical storage battery that suppresses deterioration and has improved cycle characteristics.

Further, at least one element selected from Zn, Co and Mg is solid-dissolved in nickel oxyhydroxide which is a positive electrode active material, and these elements have an effect of suppressing expansion of the positive electrode active material itself. Therefore, it is possible to suppress capacity deterioration during charge / discharge cycles. Further, by making the shape of the beta-type nickel oxyhydroxide particles spherical, the beta-type nickel oxyhydroxide has a higher density and a larger discharge capacity (battery capacity) can be obtained.

Next, a cylindrical storage battery 200 according to the second embodiment of the present invention will be described. FIG. 4 shows the configuration of the cylindrical storage battery 200 according to the second embodiment. The cylindrical storage battery 200 is an AA nickel-zinc storage battery. Further, in FIG. 1, parts corresponding to those in FIG. 6 are denoted by the same reference numerals.

This cylindrical storage battery 200 includes a battery can 2 and
It is composed of a positive electrode mixture 3, a separator 4, a negative electrode mixture 5, a current collecting pin 6, a gasket 7, a neutral cover 8, a negative electrode terminal 9, and a perforated metal cylinder 12.
4, parts corresponding to those in FIG. 1 are designated by the same reference numerals. The battery can 2 is formed by pressing a metal plate plated with nickel, for example. The battery can 2 also serves as the positive electrode terminal of the cylindrical storage battery 200.

The positive electrode mixture 3 is mixed with beta-type nickel oxyhydroxide as a positive electrode active material, carbon powder as a conductive agent, and an alkaline aqueous solution as an electrolytic solution, and is filled in the separator 4. Graphite powder is used as the carbon powder used as the conductive agent. As the alkaline aqueous solution, for example, an aqueous potassium hydroxide solution is used, but an aqueous solution of lithium hydroxide, sodium hydroxide or the like or a mixture thereof can also be used.

This positive electrode mixture 3 is manufactured as follows. First, beta-type nickel oxyhydroxide, graphite powder, and an aqueous potassium hydroxide (KOH) solution having a concentration of 40% are weighed at a weight ratio of 10: 1: 1 and mixed by a stirring method such as an impeller or a ball mill. In addition, nickel oxyhydroxide used in beta type for the positive electrode mixture 3 is manufactured by a chemical oxidation method, and the shape of the particles is spherical,
A solid solution of at least one selected from Zn, Co, and Mg was used.

The separator 4 has a bottomed cylindrical shape,
It is arranged inside the negative electrode mixture 5. For example, as the separator 4, a non-woven fabric of synthetic fibers having good liquid absorption and liquid retention properties and excellent alkali resistance is used.

The negative electrode mixture 5 has a hollow cylindrical shape and is arranged inside the battery can 2. This negative electrode mixture 5 is obtained by uniformly dispersing and mixing granular zinc and zinc oxide, which are negative electrode active materials, in an aqueous solution of potassium hydroxide, which is an electrolytic solution, using a gelling agent.

The perforated metal cylinder 12 is arranged between the positive electrode mixture 3 and the separator 4, and is a punching metal made of metal such as stainless steel, nickel, copper, tin, a metal net, or an expanded metal.

The metal that can be used as the perforated metal cylinder depends on the type of the electrolytic solution of the storage battery and the type of the positive electrode and the negative electrode. For example, in the case of a nickel-zinc storage battery, an alkaline solution, a positive electrode, stainless steel that does not react with the negative electrode, nickel,
Metals such as copper and tin can be used.

The opening of the battery can 2 is sealed by an insulating gasket 7, a neutral cover 8 and a positive electrode terminal 11. A metal collector pin 6 is welded to the positive electrode terminal 11.

The cylindrical storage battery 200 shown in FIG. 4 is manufactured as follows. First, the negative electrode mixture 5 molded into a hollow cylinder is inserted into the battery can 2. Next, negative electrode mixture 5
Inside, the separator 4 with a bottomed cylindrical shape is inserted, and then the perforated metal cylinder 12 processed into a hollow cylinder is inserted into the inside of the separator 4, and the positive electrode mixture 3 is inserted into the perforated metal cylinder 12. To fill. Finally, the battery can 2 has an insulating gasket 7,
The neutral cover 8 and the positive electrode terminal 11 are inserted, the edge of the opening of the battery can 2 is bent inward, and the gasket 7
To fix. When inserting the gasket 7 etc. into the battery can 2,
The collector pin 6 welded to the positive electrode terminal 11 is inserted into the positive electrode mixture 3.

In the cylindrical storage battery 200 shown in FIG. 4,
The current collection of the positive electrode is ensured by inserting the current collecting pin 6 welded to the positive electrode terminal 11 into the positive electrode mixture 3. Further, the current collection of the negative electrode is ensured by connecting the negative electrode mixture 5 and the battery can 2. The outer peripheral surface of the battery can 2 is
It is covered with an outer label 10 on which the manufacturer's name, battery type, precautionary notes, etc. are written, and the negative electrode terminal 9 is located at the bottom of the battery can 2. The charging / discharging reaction in the cylindrical storage battery 200 is performed according to the above equations (1) to (6).

The cylindrical storage battery 200 shown in FIG. 4 was evaluated for cycle characteristics by measuring the discharge capacity under the same test conditions as the cylindrical storage battery 100 of the first embodiment. Here, the following cylindrical batteries 200 of Examples 22 to 27 and Comparative Example 2 were examined.

In Examples 22 to 27, 10 g of the negative electrode mixture 5 prepared by mixing zinc powder, a gelling agent and a 40% KOH electrolyte at a ratio of 88: 2: 10 and adding a small amount of the additive was used. This is a battery can 2 with an outer diameter of 13.3 mm and an inner diameter of 1
It was molded into a hollow cylinder having a diameter of 0.0 mm and a height of 40 mm. The bottomed cylindrical separator 4 having a thickness of 0.2 mm is inserted therein, and then the inside of the separator 4 is processed as a perforated metal cylinder 12 into a hollow cylindrical shape having an outer diameter of 9.6 mm and a height of 40 mm. Thickness 30, 50, 100, 150, 200, 25
Insert 0 μm stainless steel punching metal, inject 2.5 g of electrolyte, and then apply beta-type nickel oxyhydroxide: graphite powder: 40% KOH electrolysis 10: 1: 1.
Then, 7.5 g of the positive electrode mixture 3 mixed in the above ratio was filled, and each battery was manufactured according to the manufacturing procedure of the cylindrical storage battery 200 described above.

In Comparative Example 2, zinc powder, similar to Examples 22 to 27, except that the perforated metal cylinder 12 was not arranged,
A gelling agent and 40% KOH electrolytic solution were mixed at a ratio of 88: 2: 10, and a negative electrode mixture prepared by adding a trace amount of the additive was used.
g was molded into a battery can 2 into a hollow cylinder having an outer diameter of 13.3 mm, an inner diameter of 10.0 mm and a height of 40 mm.
Insert the separator 4 with a thickness of 0.2 mm into
Beta-type nickel oxyhydroxide:
7.5 g of a positive electrode mixture prepared by mixing graphite powder: 40% KOH electrolysis at a ratio of 10: 1: 1 was filled, and a battery was manufactured according to the procedure for manufacturing the cylindrical storage battery 200 described above.

In addition, beta-type nickel oxyhydroxide used in the positive electrode mixture 3 of Comparative Example 2 and Examples 22 to 27 was manufactured by the chemical oxidation method, and the shape of the particles was spherical. A solid solution of at least one selected from Mg was used. Comparative Example 2 and Example 2
Table 5 shows the results of measuring 2 to 27 under the above-mentioned test conditions.

[0072]

[Table 5]

From the measurement results shown in Table 5, the relationship curve between the thickness of the punching metal made of stainless steel and the capacity retention ratio shown in FIG. 5 can be obtained. According to FIG. 5, by providing the perforated metal cylinder 12, the thickness of the perforated metal cylinder 12 in which the capacity retention rate of the battery increases after 50 cycles is in the range of 50 to 200 μm. When the thickness is 100 to 150 μm, a higher capacity retention rate can be obtained. That is, the capacity deterioration due to the charge / discharge cycle depends on the thickness of the perforated metal cylinder, for example, 50 μm.
If it is thinner than the above, the positive electrode active material expands similarly to the case without the perforated metal cylinder 12. Further, when the thickness is thicker than 200 μm, the distance between the positive electrode mixture 3 and the separator 4 becomes long, so that it becomes difficult to efficiently move water from the positive electrode to the negative electrode. Therefore, the thickness of the perforated metal cylinder 12 is
When the thickness is in the range of 50 to 200 μm, expansion of the positive electrode is suppressed, and a cylindrical storage battery with improved cycle characteristics can be obtained.

As described above, the negative electrode made of the negative electrode mixture 5 molded in the hollow cylindrical shape and the positive electrode made of the positive electrode mixture 3 filled in the hollow portion of the negative electrode via the bottomed cylindrical separator 4 are provided. In the cylindrical storage battery having, a perforated metal cylinder 12 such as a punching metal made of stainless steel, nickel, copper or tin, a metal net or an expanded metal is provided between the positive electrode mixture 3 and the separator 4, and the perforated metal cylinder 12
The thickness of 50 to 200 μm, the expansion of the positive electrode due to the moisture generated in the positive electrode during charging is suppressed, whereby the moisture generated in the positive electrode is efficiently transferred to the negative electrode, and the capacity due to the charge / discharge cycle is increased. It is possible to obtain a cylindrical storage battery that suppresses deterioration and has improved cycle characteristics.

Further, at least one element selected from Zn, Co and Mg is solid-dissolved in nickel oxyhydroxide which is the positive electrode active material, and these elements have an effect of suppressing expansion of the positive electrode active material itself. Therefore, it is possible to suppress capacity deterioration during charge / discharge cycles. Further, by making the shape of the beta-type nickel oxyhydroxide particles spherical, the beta-type nickel oxyhydroxide has a higher density and a larger discharge capacity (battery capacity) can be obtained.

In the above embodiments, the case where punching metal, metal net, and expanded metal are used has been described, but the present invention is not limited to this.
Other perforated metal cylinders may be used.

Further, in the above-mentioned embodiment, the perforated metal cylinder 12 is made of stainless steel, nickel, copper or tin alone, but a metal surface such as a metal plated with stainless steel is coated with another metal. The same effect can be obtained with metal.

Further, in the above-mentioned embodiment, the nickel-zinc storage battery is taken as an example, but the present invention is not limited to this. It is also effective for a cylindrical storage battery using an inside-out type structure such as a nickel-cadmium storage battery, a nickel-hydrogen storage battery, and a nickel-iron storage battery.

Further, in the above-mentioned embodiment, the shape of the beta-type nickel oxyhydroxide particles is spherical, but when the shape of the beta-type nickel oxyhydroxide particles is not spherical, the discharge capacity is lowered. However, the effect of improving cycle characteristics can be obtained by specifying the range of the addition amount similar to the above.

Further, in the above-described embodiment, the beta-type nickel oxyhydroxide obtained by the chemical oxidation method was used, but the invention is not limited to this. For example, you may use what was obtained by the electrochemical method.

[0081]

According to the cylindrical storage battery of the present invention,
Consisting of a hollow cylindrical positive electrode and a negative electrode arranged in the hollow part of the positive electrode via a bottomed cylindrical separator, or arranged in the hollow part of the negative electrode via a hollow cylindrical negative electrode and a bottomed cylindrical separator It is to provide a perforated metal cylinder having a predetermined thickness between the positive electrode of the cylindrical storage battery composed of the positive electrode and the separator, and to suppress the expansion of the positive electrode due to the moisture generated in the positive electrode during charging, thereby It is possible to efficiently move the generated water to the negative electrode, suppress the capacity deterioration due to charge / discharge cycles, and obtain a cylindrical storage battery with improved cycle characteristics.

Further, since at least one element selected from Zn, Co and Mg is solid-dissolved in nickel oxyhydroxide which is the positive electrode active material, these elements suppress the expansion of the positive electrode active material itself. Since it has the effect, it is possible to suppress the capacity deterioration of the charge / discharge cycle.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a storage battery according to a first embodiment.

FIG. 2 is a diagram showing the relationship between the thickness of a perforated metal cylinder and the capacity retention rate.

FIG. 3 is a diagram showing a relationship between a metal type and a capacity retention rate.

FIG. 4 is a diagram showing a configuration of a storage battery according to a second embodiment.

FIG. 5 is a diagram showing the relationship between the thickness of stainless steel punching metal and the capacity retention rate.

FIG. 6 is a diagram showing a configuration of a conventional nickel-zinc storage battery.

[Explanation of symbols]

1 ... Nickel-zinc storage battery, 2 ... Battery can, 3 ...
・ Positive electrode mixture, 4 ... Separator, 5 ... Negative electrode mixture,
6 ... collector pin, 7 ... gasket, 8 ... neutral cover, 9 ... negative electrode terminal, 10 ... exterior label, 11 ... positive electrode terminal, 12 ... perforated metal cylinder ,
100,200 ... Cylindrical storage battery

Claims (12)

[Claims] 1. A cylindrical storage battery having a positive electrode made of a positive electrode mixture formed in a hollow cylindrical shape, and a negative electrode made of a negative electrode mixture filled in the hollow portion of the positive electrode via a bottomed cylindrical separator. The cylindrical storage battery according to claim 1, wherein a perforated metal cylinder having a predetermined thickness is provided between the positive electrode and the separator. 2. The perforated metal cylinder has a thickness of 50 to 200.
The cylindrical storage battery according to claim 1, wherein the cylindrical storage battery has a thickness of μm and is made of at least one metal selected from stainless steel, nickel, copper, and tin. 3. The cylindrical storage battery according to claim 1, wherein the perforated metal cylinder is any one of punching metal, metal net, and expanded metal. 4. The cylindrical storage battery according to claim 1, wherein the positive electrode mixture contains beta-type nickel oxyhydroxide manufactured by a chemical oxidation method as a positive electrode active material. 5. The positive electrode mixture contains, as a positive electrode active material, beta-type nickel oxyhydroxide containing at least one selected from Zn, Co and Mg in a solid solution state. The cylindrical storage battery described. 6. The cylindrical storage battery according to claim 1, wherein the negative electrode mixture contains zinc as a negative electrode active material. 7. A cylindrical storage battery having a negative electrode made of a negative electrode mixture formed in a hollow cylindrical shape, and a negative electrode made of a positive electrode mixture filled in the hollow portion of the negative electrode via a bottomed cylindrical separator. The cylindrical storage battery according to claim 1, wherein a perforated metal cylinder having a predetermined thickness is provided between the positive electrode and the separator. 8. The perforated metal cylinder has a thickness of 50 to 200.
The cylindrical storage battery according to claim 7, wherein the cylindrical storage battery has a thickness of μm and is made of a metal selected from stainless steel, nickel, copper, and tin. 9. The cylindrical storage battery according to claim 7, wherein the perforated metal cylinder is any of punching metal, metal net, and expanded metal. 10. The cylindrical storage battery according to claim 7, wherein the positive electrode mixture contains, as a positive electrode active material, beta-type nickel oxyhydroxide manufactured by a chemical oxidation method. 11. The positive electrode mixture contains beta-type nickel oxyhydroxide containing at least one selected from Zn, Co and Mg in a solid solution state as a positive electrode active material. The cylindrical storage battery described. 12. The cylindrical storage battery according to claim 7, wherein the negative electrode mixture contains zinc as a negative electrode active material.