JPH06325771A - Manganese dry cell - Google Patents

Abstract

PURPOSE:To provide a mercury-free manganese dry cell which prevents the internal resistance of the cell from being increased during preservation or when discharge takes place at low loading less than 10OMEGA, restrains intermittent discharge characteristics from being degraded, and concurrently has characteristics identical to these of a former mercury contained manganese dry cell. CONSTITUTION:The mercury-free and manganese-free dry cell comprises its negative electrode 1 faced to positive electrode binder 3 via a separator 2. In the manganese dry cell, the total amount of indium compound and bismuth compound, which is 0.05 to 10.0% sizing agent by weight, is added to the sizing agent interposed between the negative electrode and the separator. Or facial active agent in a cation system may be added by 0.002 to 0.2vol.% to electrolyte in the sizing agent.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a manganese dry battery,
This is to improve the discharge characteristics without adding mercury.

[0002]

2. Description of the Related Art Conventionally, a manganese dry battery using manganese dioxide as a positive electrode active material, zinc as a negative electrode active material, and an aqueous solution containing zinc chloride as a main component as an electrolyte is known. In such a manganese dry battery, the internal resistance rises during storage, and when discharged with a load lighter than 10Ω, the internal resistance rises during discharge, which deteriorates the discharge characteristics particularly in intermittent discharge. There was a problem.
Such a phenomenon is particularly remarkable in a battery to which mercury, lead or cadmium is not added in order to make the dry battery pollution-free, which has been strongly desired in recent years.

[0003]

In order to solve this problem, the amount of the electrolytic solution in the positive electrode mixture has been increased or the amount of the carbon material such as acetylene black, which is a conductive agent, has been increased. Moreover, various improvements such as selection of a separator paste (starch) have been attempted, but satisfactory results have not yet been obtained. That is, increasing the blended amount of the electrolytic solution causes the leakage of the battery to increase, and increasing the conductive agent inevitably reduces the amount of manganese dioxide in the positive electrode mixture, resulting in a decrease in discharge capacity. Further, even if the sizing agent is changed to suppress the increase of the internal resistance during storage or light load discharge of 10Ω or less, there is a problem that the discharge characteristics of heavy load such as 2Ω, 4Ω are deteriorated.

The present invention suppresses such an increase in internal resistance during storage or a discharge under a light load of 10 Ω or less and deterioration of intermittent discharge characteristics accompanying it, and is comparable to a conventional mercury-containing manganese dry battery. It is an object of the present invention to provide a mercury-free manganese dry battery having the following performance.

[0005]

In the manganese dry battery of the present invention, an indium compound and a bismuth compound are allowed to coexist in a sizing agent applied to a separator base material, and the total amount thereof is 0.05 to 10 with respect to the sizing agent. It is characterized in that 0.0% by weight is added. Examples of the indium compound used in the present invention include metal In, In ₂ O ₃ , In (OH) ₃ , and I.
nCl ₂ , In ₂ (SO ₄ ) _{3 and the} like can be exemplified, and as the bismuth compound, metal Bi, Bi ₂ O ₃ , Bi (OH)
₃ and BiCl ₃ can be exemplified. Such a compound is added as a component of the sizing agent. Further, 0.002 to 0.2% by volume of a cationic surfactant may be added to the electrolytic solution in the paste.

[0006]

In the manganese dry battery of the present invention, the metal indium deposited on the zinc surface and the metal bismuth reduce the dissolution of zinc during storage, so that the internal resistance of the battery can be suppressed. Further, since the reaction of the zinc surface during discharge is made uniform and the diffusion of the discharge product is improved, the increase in internal resistance is suppressed. Further, the amount of indium and bismuth to be added to the paste of the separator is preferably in the range of 10% by weight to 0.05% by weight. If the total amount is less than 0.05% by weight, there is an effect, but it is not sufficient, and 10% by weight
This is because if the content exceeds the range, the deposited indium and bismuth serve as resistance components, which may rather reduce the discharge performance.

Regarding the effect of adding the cationic surfactant active agent, the cationic surfactant active agent adsorbed on the zinc surface suppresses corrosion. If the added amount is less than 0.002% by volume with respect to the electrolytic solution, satisfactory corrosion resistance cannot be obtained, but there is some effect. Also, 0.2% by volume
If it exceeds, there is an effect of suppressing corrosion, but it is not preferable because it causes potential deterioration and performance deterioration.

[0008]

EXAMPLES The present invention will be described in detail with reference to Examples, Comparative Examples and Reference Examples. FIG. 1 is a sectional view of an embodiment of the present invention. In the figure, reference numeral 1 is a negative electrode zinc can containing no mercury, and a separator 2 having a glue layer made of starch, synthetic paste, etc. formed inside the zinc can 1 contacts the zinc can 1 with the glue layer. It is stored in. Inside the separator 2 is a carbon rod 4
Is filled in with the positive electrode mixture 3 embedded in the center. The positive electrode mixture 3 is a molded body in which manganese dioxide, a conductive agent such as acetylene black or graphite, and an electrolytic solution of zinc chloride or ammonium chloride are mixed. 5 is a plastic sealing body in which the central carbon rod 4 is inserted. 6 is a metal positive electrode terminal plate fitted on the top of the carbon rod 4, and 7 is a metal negative electrode terminal plate abutting on the outer bottom of the zinc can 1.
Reference numeral 9 is a heat-shrinkable, flexible, cross-linked polyolefin tube that encloses the outer peripheral wall of the zinc can, and 8 is a metal outer can that is bent at the upper and lower terminals to seal the entire dry battery.

Examples 1 to 21 The separator used in the mercury-free manganese dry battery of the present invention was prepared by adding Bi ₂ O ₃ and In (OH) ₂ to a paste paste containing an aqueous solution of polyvinyl alcohol, starch and a surfactant activator. Add ₃ and stir well to disperse uniformly. At this time, the sizing agent and the electrolytic solution are added in the composition as shown in Table 1, and these pastes are applied to a kraft paper material and dried to obtain a separator 2. Using these, an R20 type mercury-free manganese dry battery was prototyped.

[0010]

[Table 1]

Comparative Examples 1 to 13 The same operations as those in the above-mentioned examples were carried out except that the amounts of Bi ₂ O ₃ and In (OH) and the surfactant added to the paste paste were changed as shown in Table 2. , R20 type manganese dry battery was prepared.

[0012]

[Table 2]

Reference Examples 1 and ₂ Reference example 1 shows a formulation in which the amounts of Bi ₂ O ₃ and In (OH) ₃ added to the paste paste were zero, and reference example 2 shows the performance of the mercury-containing battery. The structure of the battery and the materials used are the same as those of the above-mentioned examples and comparative examples.

The dry batteries shown in the above-mentioned Examples, Comparative Examples and Reference Examples were stored at 45 ° C. for 3 months, and each dry battery was continuously discharged at 300Ω, and the internal resistance (Ω) after discharging to 0.9V was displayed. Shown in 3. Each measurement was performed 10 times and the average value was shown. Further, the prototype battery was discharged at 20 ° C. for 7 days and then discharged at 20Ω for 4 hours a day, and the duration (h) up to 0.9 V was measured and shown in the table. Each measurement was performed 10 times and the average value was shown.

[0015]

[Table 3]

[0016]

As is apparent from the above table, Bi is contained in the paste material.
_The manganese dry battery with ₂ O ₃ and In (OH) ₃ added is
In the range of 10% by weight to 0.05% by weight, the effect is as good as that of the mercury-containing battery, and the effect is clear. Further, it is found that it is effective to use a cationic surfactant together. From the above, the present invention suppresses an increase in internal resistance after storage, medium load, and light load discharge,
A manganese dry battery with good discharge performance can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an R20 type manganese dry battery according to the present invention.

[Explanation of symbols]

 1 zinc can 2 separator 3 positive electrode mixture

Claims (3)

[Claims] 1. In a manganese dry battery in which a negative electrode and a positive electrode mixture are opposed to each other via a separator, indium or the same compound and bismuth or the same compound are contained in the sizing agent between the negative electrode and the separator in a total amount of the sizing agent. To 0.05-1
A manganese dry battery characterized by being added so as to be 0.0% by weight. 2. The manganese dry battery according to claim 1, wherein a cationic surfactant is added to the electrolytic solution in the sizing agent. 3. The manganese according to claim 2, wherein the cationic surfactant is a monoalkyl quaternary ammonium chloride, which is added in an amount of 0.002 to 0.2% by volume with respect to the electrolytic solution. Dry batteries.