JPH103915A - Positive electrode active material for alkaline-manganese battery, and alkaline-manganese battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery having a high capacity and a high utilization factor, allowing an electric discharge for a long time, and suppressing a self-discharge even if the added quantity of carbon powder is small by containing tin oxide fibers in manganese dioxide serving as a positive electrode active material. SOLUTION: Zinc oxide of 2% is dissolved in a potassium hydroxide having the concentration of 35% for use as an electrolyte. Tin oxide fibers or graphite powder of 10wt.% and the electrolyte of 4wt.% are added to electrolytic manganese dioxide and kneaded to mold hollow pellets, the hollow pellets are inserted into a nickel-plated steel cylinder can container and pressurized, a separator made of a bag-like polyamide fiber nonwoven fabric is inserted into a hollow section, the electrolyte is injected, and a positive electrode active material is impregnated with the electrolyte. The electrolyte and polyacrylic sodium are added to zinc powder and kneaded to obtain a negative electrode active material, the negative electrode active material is injected into the separator, a nickel wire is inserted into the center section as a current collector, one end is guided to the outside, and the mouth of the separator is bound with a nylon thread to form a simplified test battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel positive electrode active material for an alkaline manganese battery and an alkaline manganese battery using the same.

[0002]

2. Description of the Related Art Portable audio equipment, which is rapidly spreading today,
As a power source for portable devices such as portable terminals, high capacity,
There is a demand for a battery that can be operated for a long time.
There are two types of batteries, primary batteries such as dry batteries that consumers can use immediately after purchase, and secondary batteries that can be used repeatedly by recharging. Is used properly. Among primary batteries, an alkaline manganese battery has a higher capacity than a manganese battery, and its demand is growing as a battery that can operate a portable device or the like for a long time.

In an alkaline manganese battery, an alkaline aqueous solution is used as an electrolyte and manganese dioxide (hereinafter also referred to as MnO ₂ ) is used as a positive electrode active material. The discharge reaction in the alkaline manganese battery generally proceeds according to the following equation.

Negative electrode: Zn + 4OH ⁻ → Zn (OH) ₄ ²⁻ + 2e ⁻ (1) Positive electrode: 2MnO ₂ + 2H ₂ O + 2e ⁻ → 2MnOOH + 2OH ⁻ (2) That is, in the positive electrode, manganese dioxide (Mn) as a positive electrode active material
O ₂ ) reacts with water (H ₂ O) in the aqueous alkali solution to form manganese oxyhydroxide, generating a hydroxyl group (OH ⁻ ).
In the negative electrode, a hydroxyl group generated in the positive electrode and a hydroxyl group in an alkaline aqueous solution react with zinc (Zn), which is a negative electrode active material,
It becomes Zn (OH) ₄ ²⁻ and generates electrons (e ⁻ ).

[0005] Since the electrical conductivity of manganese oxyhydroxide generated at the positive electrode after discharge is very poor, it is one-third of the theoretical capacity.
When the discharge proceeds to the extent that the amount of manganese oxyhydroxide generated increases, it becomes difficult for electrons to reach unreacted manganese dioxide, the electromotive force is reduced, and it is not possible to perform high-load discharge any more. There is a problem that the utilization rate of the garbage is reduced.

Therefore, in order to improve the utilization rate of the positive electrode active material, it has been proposed to contain about 5 to 15% by weight of a carbon powder such as graphite powder or acetylene black as a conductive agent (see, for example, Japanese Patent Application Laid-Open No. -245109, JP-A-7-272715).

However, in the alkaline aqueous electrolyte solution, the carbon powder contained in the positive electrode active material is gradually oxidized and consumed by manganese dioxide, and carbon dioxide or a carbonate such as potassium carbonate is formed to form a carbon dioxide in the alkaline aqueous solution. There has been a problem that the alkali concentration decreases, self-discharge proceeds, and long-term discharge cannot be performed. This self-discharge could not be sufficiently suppressed even if the type of carbon powder was changed.

When the content of the carbon powder in the positive electrode active material is increased, the electric conductivity of the positive electrode active material is improved, but the specific gravity of the carbon powder is light and bulky. In a battery whose size is limited as described above, the filling amount of manganese dioxide is reduced, and the capacity of the battery is reduced. On the other hand, when the content of the carbon powder in the positive electrode active material is reduced, the electric conductivity of the positive electrode active material decreases, and the utilization rate decreases. As described above, there is a limit to the possibility of discharging for a long time by increasing the filling amount of manganese dioxide as much as possible to increase the capacity and improve the electric conductivity of the positive electrode active material to improve the utilization factor. there were.

[0009]

Accordingly, an alkaline manganese battery which has a high capacity and a high utilization rate even with a small amount of carbon powder added, enables a long-time discharge and suppresses self-discharge. The development of a positive electrode active material has been strongly desired.

[0010]

Means for Solving the Problems The present inventors have intensively studied to solve the above technical problems. as a result,
By using a positive electrode active material containing tin oxide fibers as a positive electrode active material for an alkaline manganese battery, it has a high capacity and a high utilization even with a small amount of carbon powder added,
The present inventors have found that long-term discharge is possible and that self-discharge is suppressed, and have completed the present invention and have proposed the present invention.

That is, the present invention relates to a positive electrode active material for an alkaline manganese battery, characterized in that manganese dioxide contains tin oxide fibers. Another invention relates to an alkaline manganese battery, wherein a positive electrode in which a current collector is filled with the positive electrode active material for an alkaline manganese battery and a negative electrode are housed in a container together with an electrolytic solution via a separator.

Hereinafter, the present invention will be described in detail.

The alkaline manganese battery of the present invention is characterized in that it has an electrolyte solution composed of an aqueous alkali solution, and further has a positive electrode having a positive electrode active material containing manganese dioxide and a negative electrode active material containing zinc. It refers to a primary battery composed of a negative electrode, a negative electrode current collector, a separator, a container for accommodating them, and the like. The battery reaction is as shown in Equations 1 and 2. According to Japanese Industrial Standards (JIS), the alkaline manganese battery is
It is commercially available under specifications such as a single type 1 (LR03) and a single type 5 (LR20).

The positive electrode active material for an alkaline manganese battery according to the present invention is generally a material containing manganese dioxide in which the reaction of the formula 2 is caused by discharge. Manganese dioxide includes electrolytic manganese dioxide and chemically adjusted manganese dioxide, and electrolytic manganese dioxide is generally used because of its higher utilization. Further, a binder such as methylcellulose may be added to the positive electrode active material so as to be easily sealed in the battery. The present invention is characterized in that the positive electrode active material comprising manganese dioxide contains tin oxide fibers.

The positive electrode active material containing tin oxide fibers is usually produced as follows. First, manganese dioxide powder, tin oxide fiber,
And / or kneading a binder or the like with a solvent such as water or an electrolytic solution to produce a paste or aggregate of a positive electrode active material containing tin oxide fibers. After kneading manganese dioxide and a solvent first, tin oxide fibers may be kneaded. At this time, if the amount of the solvent is small and the particles are aggregated, the subsequent molding is easier. After the paste or aggregate is manufactured, it is formed into pellets using a die and a press, and dried. In the case of a cylindrical alkaline manganese battery, it is formed into a hollow circular pellet (several mm to several cm in diameter, several mm to several cm in length), and several of these circular pellets are stacked to form a hollow long tube. In many cases, a negative electrode active material and / or a negative electrode current collector are inserted into the space. Further, tin oxide fibers may be slightly crushed or cut during the production of pellets.

As the negative electrode active material, zinc powder or a material obtained by mixing an electrolytic solution and a gelling agent with zinc powder and gelling the mixture by stirring is used. After mixing the zinc powder and the gelling agent, the electrolyte may be injected. Zinc dissolves in the electrolyte,
A zinc powder containing an alloy element such as indium, lead, or aluminum is often used so as not to generate hydrogen gas.

An alkaline aqueous solution as an electrolytic solution is usually
An aqueous solution of potassium hydroxide having a concentration of about 35 to 40% is used. Further, another alkali such as sodium hydroxide (NaOH) or an aqueous potassium hydroxide solution in which zinc oxide (ZnO) or the like is dissolved may be used. The electrolytic solution is impregnated into each active material by a method such as mixing each active material when kneading it into a paste, or injecting each active material after inserting it into a container.

As the separator, a nonwoven fabric made of polyamide fiber, vinylon fiber (acetalized polyvinyl alcohol), vinylon fiber (copolymer of vinyl chloride and vinyl acetate), polyolefin fiber, natural fiber, rayon fiber and the like is used. In addition, two or more kinds of substances may be used in combination, such as the combination of the nonwoven fabric and cellophane.

The positive electrode and the negative electrode are housed in a container together with an electrolyte and the like via a separator. There are types of alkaline manganese batteries such as cylindrical type and button type, and depending on the type, the container may be divided into a positive electrode container, a negative electrode container, an outer can, etc., or the container may serve as a current collector .

In a cylindrical alkaline manganese battery,
Usually, the separator is a bag-shaped separator, a negative electrode active material and a rod-shaped negative electrode current collector are inserted into the separator, and the separator is housed in a positive electrode container so that the positive electrode active material is installed around the separator. It is inserted into an outer can. At this time, a nickel wire, a brass wire, or the like is used for the negative electrode current collector, the negative electrode container is not used, and the positive electrode container corresponds to the positive electrode current collector.

On the other hand, in a button-type alkaline manganese battery, a positive electrode container usually contains a positive electrode active material, a separator,
The negative electrode active material is sequentially filled, and the container is covered with a negative electrode container. At this time, each container serves as a current collector. In both the cylindrical and button type alkaline manganese batteries, the positive electrode container and the negative electrode container are usually made of nickel-plated steel or nickel in many cases.

Suitable tin oxide fibers for use in the present invention include fibrous shaped articles of 50 mol% or more of tin oxide having an aspect ratio of 10 or more.

The shape of the tin oxide fiber is not particularly limited, and the cross section of the fiber may have any shape. The cross section of the fiber is usually circular, elliptical, or polygonal such as triangular or quadrangular, although it varies depending on the production method and conditions of the tin oxide fiber. If the cross section is circular, the diameter is equivalent to the minor axis, if the ellipse is the average of the shorter and longer diameters is equivalent to the minor axis, and if the polygon is the shortest diagonal and the longest The average of the diagonal lines corresponds to the minor axis. However, when the cross section is a triangle, the average of the shortest side and the longest side corresponds to the minor axis.

The smaller the minor axis of the tin oxide fiber is,
It is preferable because the mechanical strength such as the tensile strength is large and the flexibility is improved, but tin oxide fiber having a too small short diameter is difficult to produce. The minor diameter of the tin oxide fiber is 0.5
-100 μm is desirable, 1-60 μm is more preferred, and 1-40 μm is more preferred.

The major axis of the tin oxide fiber is defined as the length of the fiber cross section in the normal direction, that is, the length of the fiber in the longitudinal direction. When the major axis of the tin oxide fiber is too short and the aspect ratio is small, the effect of imparting electric conductivity when added to the positive electrode active material is small, and when the major axis is too long and the aspect ratio is large, the positive electrode active material is reduced. There is a high possibility that the particles are dispersed non-uniformly therein, and the effect of imparting electric conductivity may be reduced. Therefore, the aspect ratio of the tin oxide fiber is preferably from 10 to 20,000, and more preferably from 20 to 1,000.

The values of the minor axis and major axis are at least 10
The average value of tin oxide fibers or more is used. The values of the minor axis and major axis can be easily measured using a photograph of the tin oxide fiber taken with a scanning electron microscope, an optical microscope, or the like, to which a photographing device is attached.

The tin oxide in the tin oxide fiber is a tin oxide such as tin dioxide (SnO ₂ ), tin monoxide (SnO), or tin oxide having an oxygen deficiency (SnO _2-x , where 0 <X <1). There is a case where a plurality of tin oxides having different chemical compositions exist as oxides. What kind of chemical composition of tin oxide is contained in the tin oxide fiber varies depending on manufacturing conditions such as the atmosphere during firing. For example, if the atmosphere is an oxidizing atmosphere such as oxygen or air at the time of firing, most of the tin oxide is tin dioxide or tin oxide fibers having a high content of tin dioxide, and an inert atmosphere such as argon gas or helium gas is used. Or a non-oxidizing atmosphere such as a reducing atmosphere such as carbon monoxide, contains tin monoxide and tin oxide having oxygen defects in addition to tin dioxide, and most of tin oxide is tin monoxide or oxygen. The tin oxide fiber is a tin oxide having defects. Among them, tin oxide fibers in which most of tin oxide is tin dioxide are preferable because of their high mechanical strength.

The amount of tin oxide in the tin oxide fiber is preferably at least 60 mol%, more preferably at least 70 mol%, in order to improve mechanical strength and electric conductivity.

As a component other than tin oxide, a doping component was added to the tin oxide fiber to control electric resistivity, and an additional component was added to further improve mechanical strength. Is better. However, a plurality of doping components or additive components may be added at the same time.

It is preferable that the total amount of components other than tin oxide such as doping components and additive components does not exceed the amount of tin oxide, that is, the ratio is less than 50 mol%. However, generally such Sb ₂ O ₅ type M _m O _n (M; cation,
When an oxide containing m cations represented by m ≧ 2 and n ≧ 1) is present in the tin oxide fiber, doping is performed depending on the number of moles of the cations or elements contained in the tin oxide fiber. Calculate the proportions of the components and additional components. For example, Sn / Sb (molar ratio) = 9/1 in tin oxide fiber
In the case where Sb is present, even if Sb exists in the state of Sb ₂ O ₅ , it is assumed that Sb is contained at 10 mol%.

As the doping component, an oxide containing an element of Group 15 of the periodic table (new IUPAC method) such as antimony and bismuth, or a fifth element such as vanadium and niobium is used.
There is an oxide containing a group element. Among these, antimony oxide is preferable because the effect of lowering the electrical resistivity is extremely high.

The optimum amount of the doping component is selected each time according to the performance and cost of the alkaline secondary battery. However, if the amount is too small, the effect of lowering the electrical resistivity is generally small, and the amount is too small. If the number is too large, the cost will increase, or phase separation will occur, causing inconvenience such as lowering the mechanical strength. Therefore, the amount of the doping component is desirably 0.1 to 30 mol% based on the total number of moles of tin and the doping component.
Molar% is more preferred.

On the other hand, as the additional components, Group 3 elements such as oxides containing Group 2 elements such as calcium and magnesium, yttrium and lanthanoids (elements having an atomic number of 57 to 71 such as lanthanum and cerium) are used. Oxides containing, oxides containing Group 4 elements such as titanium and zirconium, oxides containing Group 5 elements such as vanadium and niobium, oxides containing Group 6 elements such as chromium, manganese, etc. An oxide containing a Group 12 element such as zinc, an oxide containing a Group 12 element such as zinc, an oxide containing a Group 13 element such as aluminum or indium,
Examples of the oxide include an oxide containing a Group 14 element such as silicon and germanium, and an oxide containing a Group 15 element of the periodic table such as antimony and bismuth. Among them, oxides containing Group 13 elements such as aluminum and indium,
Alternatively, an oxide containing a Group 4 element such as titanium or zirconium is preferable because it has a high effect of improving mechanical strength.

The optimum amount of the additive component is selected each time according to the performance and cost of the alkaline manganese battery.
In general, the larger the amount, the higher the effect of improving the mechanical strength. However, if the amount is too large, phase separation or the like will occur, and on the contrary, the mechanical strength will be lowered. Therefore, the amount of the additional component is desirably 40 mol% or less, more preferably 30 mol% or less, based on the total number of moles of tin and the additional component. However,
Since silicon oxide such as SiO ₂ is easily dissolved in an aqueous alkali solution, when it is contained as an additional component in the tin oxide fiber of the present invention, the content is preferably 30 mol% or less, and 15 mol% or less.
Mole% or less is more preferable.

The tin oxide fiber is made of amorphous, polycrystalline, or single crystal tin oxide, depending on the production conditions. However, when the addition amount of other components other than tin oxide such as doping components and additional components is small, the other components often form a solid solution in tin oxide, but when the addition amount of other components is large, In some cases, the phase is separated from tin oxide to form another phase. The fine structure of the tin oxide fiber can be confirmed by X-ray diffraction analysis or the like. For example, in the case of amorphous, the X-ray diffraction pattern becomes halo. In the case of a polycrystal, a plurality of diffraction peaks appear from tin oxide or a separated doping component or additive component.

The electrical resistivity of the tin oxide fiber varies greatly depending on the type of the doping component, the amount added, the manufacturing conditions, and the like. Usually, it often has a value of 10 ⁴ to 10 ⁻² Ω · cm, and a tin oxide fiber having such an electric resistivity is preferable as an additive for maintaining the electric conductivity of the positive electrode active material.

The content of the tin oxide fiber in the positive electrode active material is not particularly limited. If the content is too small, the effect of imparting electric conductivity is small. If the content is too large, the amount of manganese dioxide is reduced. The ratio decreases, and the capacity of the alkaline manganese battery decreases. The content of the tin oxide fiber is preferably 0.1 to 30% by weight, more preferably 1 to 15% by weight, based on the total amount of the tin oxide fiber and manganese dioxide.

In producing the tin oxide fiber, any method may be used. For example, a solution method in which a solution containing a precursor of tin oxide is produced, or a sputtering method in which a target containing tin oxide is sputtered under argon plasma and tin oxide is deposited on a substrate having a groove, and further, tin monoxide Heat and sublimate tin compounds or tin such as in a closed container or a container close to a closed state,
It is manufactured by a precipitation method of recrystallizing tin oxide (stannic oxide) as a whisker. Among them, the solution method is preferable because the short diameter and the long diameter of the tin oxide fiber can be easily controlled, the mass productivity is excellent, and the yield is high.

The solution method includes the following methods. A tin compound such as tin halide or metal tin, and a compound containing a doping component and an additional component are sequentially dissolved in an alcohol such as methanol. After dissolution, unnecessary alcohol is concentrated under reduced pressure to obtain a viscous spinning solution. The spinning solution is extruded from a nozzle having a large number of holes having a diameter of about several μm to several mm or sucked out, and spinning is performed.
After the gel fibers are formed, baking is performed at a temperature of about 500 to 1000 ° C.

[0040]

The positive electrode active material for an alkaline manganese battery containing the tin oxide fiber of the present invention has a high capacity and a high utilization rate even with a small amount of carbon powder, and can be discharged for a long time. And has the effect of suppressing self-discharge. Further, the above effect makes it possible to reduce the addition amount of the carbon powder in the alkaline manganese battery, it is possible to increase the filling amount of the positive electrode active material in the electric field, and it is possible to perform discharge for a longer time. .

The reason why a long-time discharge is possible even when the amount of the carbon powder added is small is that the tin oxide fiber does not oxidize or decompose even under the harsh conditions of a discharge reaction in an alkaline aqueous solution, resulting in stable corrosion resistance. It is considered that the tin oxide fiber maintained the electrical conductivity of the positive electrode active material even when manganese oxyhydroxide was generated after the progress of discharge.

The reason why the self-discharge was suppressed was that, in the positive electrode active material to which carbon powder was added, manganese dioxide gradually reacted with the carbon powder and was consumed, whereas alkali manganese containing tin oxide fibers was used. In battery positive electrode active materials,
It is considered that manganese dioxide did not react with the tin oxide fiber.

[0043]

EXAMPLES Examples are shown below, but the invention is not limited to them.

In the following Examples and Comparative Examples, a discharge test of an alkaline manganese battery was performed using a simplified battery as shown below.

As the electrolytic solution, a solution prepared by dissolving 2% of zinc oxide in a 35% aqueous solution of potassium hydroxide was used. A nickel-plated steel cylindrical can (φ14 mm × 60 mm, no lid) was used as a battery container, and a bag-shaped nonwoven fabric of polyamide fiber was used as a separator.

Into 9.0 g of electrolytic manganese dioxide, tin oxide fiber or graphite powder (both 10% by weight) and 4% by weight
Was added and kneaded, and then formed into hollow pellets using a die and a press. The positive electrode active material was placed in the cylindrical can, and further pressurized with a punch having a middle rod. The center rod was removed, a separator was inserted into the hollow portion, an electrolyte was injected into the separator, and the electrolyte was impregnated with the positive electrode active material. Zinc powder (Zn-Bi0.2% -In0.0
5 g of an electrolyte solution and sodium polyacrylate were added to 10 g of (5% -Al 0.1%) to obtain a kneaded gel-like negative electrode active material, and this negative electrode active material was injected into a separator with a dropper. The amount of zinc powder in the injected negative electrode active material was about 4 g. Insert a current collector (nickel wire, φ about 2 mm x 80 mm) into the center of the separator, wrap the end of the current collector about 30 mm outside, tie the mouth of the separator with a nylon thread, A battery was configured. Liquid paraffin was placed on top of the simplified battery to prevent the electrolyte from evaporating.

This simple battery was discharged at a constant current of 1 A until the final voltage reached 0.9 V, and the discharge duration was measured. However, the above-mentioned batteries were produced two by two, and the discharge duration immediately after producing the simplified type battery and the discharge duration after producing and storing at 60 ° C. for one month (storage at room temperature for about 1.5 years) Was measured. The superiority of the self-discharge characteristic was determined based on the length of the discharge duration after storage at 60 ° C. for one month.

Example 1 639.0 g of stannous chloride (SnCl ₂ ), 5 of tin metal
49.6 g, antimony chloride (SbCl ₃ ) 95.8 g
Was sequentially dissolved in 3942 g of methanol. The obtained solution was concentrated by a rotary evaporator to obtain a spinning solution A. The spinning solution A was spun from a nozzle having many holes to produce a gel fiber. 700 ° C
After firing for 2 hours, tin oxide fibers A having an average fiber diameter of 27 μm and an aspect ratio of 370 were obtained. As a result of elemental analysis by a calibration curve using a fluorescent X-ray, Sn / Sb
The molar ratio was 94.9 / 5.1.

A positive electrode active material was prepared by adding 9.0 g of electrolytic manganese dioxide, 1 g of tin oxide fiber A, and 0.4 g of an electrolytic solution and kneading them. Assembling the simple battery as described above,
The discharge duration was measured. Table 1 shows the results.

Example 2 639.0 g of stannous chloride (SnCl ₂ ), 5 of tin metal
49.6 g, antimony chloride (SbCl ₃ ) 95.8 g
Was sequentially dissolved in 3942 g of methanol. Thereafter, tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ) 238.2
g was added. The obtained solution was concentrated by a rotary evaporator to obtain a spinning solution B. The spinning solution B was spun from a nozzle having a large number of holes to produce a gel fiber.
After firing this gel fiber at 700 ° C. for 2 hours, it is cut,
Tin oxide fibers B having an average fiber diameter of 33 μm and an aspect ratio of 303 were obtained. As a result of elemental analysis by a calibration curve using a fluorescent X-ray, a Sn / Sb / Si molar ratio = 83.5 / 4.
5 / 12.0.

A positive electrode active material was prepared by adding 9.0 g of electrolytic manganese dioxide, 1 g of tin oxide fiber B, and 0.4 g of an electrolytic solution and kneading them. Assembling the simple battery as described above,
The discharge duration was measured. Table 1 shows the results.

Example 3 639.0 g of stannous chloride (SnCl ₂ ), 5 of tin metal
49.6 g, antimony chloride (SbCl ₃ ) 95.8 g
Was sequentially dissolved in 3840 g of methanol. Thereafter, to this solution was added 133.3 g of aluminum chloride (AlCl ₃ ) dissolved in 102 g of methanol. The obtained solution was concentrated by a rotary evaporator to obtain a spinning solution C. The spinning solution C was spun from a nozzle having a large number of holes to produce a gel fiber. This gel fiber is fired at 700 ° C. for 2 hours, and then cut to obtain an average fiber diameter of 3
Tin oxide fibers C having a size of 2 μm and an aspect ratio of 313 were obtained.
As a result of elemental analysis by a calibration curve using a fluorescent X-ray,
Sn / Sb / Al molar ratio = 83.3 / 4.5 / 12.2.
Met.

A positive electrode active material was obtained by adding 9.0 g of electrolytic manganese dioxide, 1 g of tin oxide fibers, and 0.4 g of an electrolytic solution and kneading them. Assembling the simple battery as described above,
The discharge duration was measured. Table 1 shows the results.

Example 4 639.0 g of stannous chloride (SnCl ₂ ) and 5 of tin metal
49.6 g, antimony chloride (SbCl ₃ ) 95.8 g
Was sequentially dissolved in 3840 g of methanol. Thereafter, 389.2 g of tetrabutoxytitanate (Ti (OC ₄ H ₉ ) ₄ ) dissolved in 102 g of methanol was added to this solution. The obtained solution was concentrated by a rotary evaporator to obtain a spinning solution D. The spinning solution D was spun from a nozzle having a large number of holes to produce a gel fiber.
After firing this gel fiber at 700 ° C. for 2 hours, it is cut,
Tin oxide fibers D having an average fiber diameter of 32 μm and an aspect ratio of 313 were obtained. As a result of elemental analysis by a calibration curve using a fluorescent X-ray, the Sn / Sb / Ti molar ratio was 83.3 / 4.
4 / 12.3.

A positive electrode active material was prepared by adding 9.0 g of electrolytic manganese dioxide, 1 g of tin oxide fiber D, and 0.4 g of an electrolytic solution and kneading them. Assembling the simple battery as described above,
The discharge duration was measured. Table 1 shows the results.

Example 5 639.0 g of stannous chloride (SnCl ₂ ), 5 of tin metal
49.6 g, antimony chloride (SbCl ₃ ) 95.8 g
Was sequentially dissolved in 3840 g of methanol. Thereafter, 438.7 g of tetrabutoxyzirconate (Zr (OC ₄ H ₉ ) ₄ ) dissolved in 102 g of methanol was added to this solution. The obtained solution was concentrated by a rotary evaporator to obtain a spinning solution E. The spinning solution E was spun from a nozzle having a large number of holes to produce a gel fiber. The gel fiber was fired at 700 ° C. for 2 hours and then cut to obtain a tin oxide fiber E having an average fiber diameter of 34 μm and an aspect ratio of 294. As a result of elemental analysis by a calibration curve using a fluorescent X-ray, a Sn / Sb / Zr molar ratio = 83.3 /
4.3 / 12.4.

A positive electrode active material was obtained by adding 9.0 g of electrolytic manganese dioxide, 1 g of tin oxide fiber E, and 0.4 g of an electrolytic solution and kneading them. Assembling the simple battery as described above,
The discharge duration was measured. Table 1 shows the results.

COMPARATIVE EXAMPLE 1 9.0 g of electrolytic manganese dioxide, 1 g of graphite powder and 0.4 g of electrolytic solution were added and kneaded to obtain a positive electrode active material.
A simple battery was assembled as described above, and the discharge duration was measured. Table 1 shows the results.

Comparative Example 2 9.0 g of electrolytic manganese dioxide and 0.4 g of an electrolytic solution were added and kneaded to obtain a positive electrode active material. A simple battery was assembled as described above, and the discharge duration was measured. Table 1 shows the results.

[0060]

[Table 1]

Claims (3)

[Claims] 1. A positive electrode active material for an alkaline manganese battery, characterized in that manganese dioxide contains tin oxide fibers. 2. The positive electrode active material for an alkaline manganese battery according to claim 1, wherein the tin oxide fiber is composed of 50 mol% or more of tin oxide. 3. A method according to claim 1, wherein the positive electrode filled with the positive electrode active material for an alkaline manganese battery according to claim 1 or 2 and a negative electrode are contained in a container together with an electrolytic solution via a separator. Features alkaline manganese battery.