JP2992781B2 - Manganese dry cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the suppression of internal resistance rise of manganese dry batteries and the improvement of light-load / medium-load discharge.

[0002]

2. Description of the Related Art Conventionally, in a manganese dry battery using manganese dioxide, particularly natural manganese dioxide, as a positive active material, a zinc alloy as a negative active material, and an electrolyte mainly containing zinc chloride, the internal resistance has increased after storage. Was. Lighter load
When the discharge is performed at a medium load, there is a problem that the internal resistance of the battery increases during the discharge and the pulse discharge characteristics deteriorate. This is particularly noticeable in batteries that do not contain mercury for the purpose of eliminating pollution of batteries, which has been strongly desired in recent years.
Such deterioration of the pulse characteristics is very disadvantageous for applications such as pagers.

In order to solve this problem, conventionally, the amount of electrolyte in the positive electrode mixture has been increased, the amount of graphite as a conductive material has been increased, or the type of paste material for the separator has been changed. Was.

[0004]

However, increasing the amount of the electrolytic solution leads to an increase in the number of battery leaks, and increasing the amount of the conductive material involves increasing the amount of the manganese dioxide in the positive electrode mixture. The amount is reduced, resulting in a decrease in discharge capacity. Further, when the glue material is changed, even if the internal resistance after storage and during light load / medium load discharge can be suppressed from increasing, there is a disadvantage that characteristics such as heavy load discharge are reduced.

The present invention solves such a conventional problem,
An object of the present invention is to provide a mercury-free manganese dry battery that suppresses a rise in internal resistance of the battery after storage and during light load / medium load discharge and has little decrease in pulse discharge characteristics.

[0006]

The present invention relates to a manganese dry battery containing a separator having a glue layer formed on one or both sides so that the glue layer is in direct contact with the inner surface of the negative electrode zinc can. A manganese dry battery to which a compound is added.

As lead compounds, lead oxide PbO, lead chloride PbCl ₂ , lead hydroxide Pb (OH) _{2 and the} like are useful.
The amount of addition is 0.001-
Preferably, 0.1 mg / cm ^{2 is} applied.
If it is less than 0.001 mg / cm ² , practical effects cannot be obtained, and if it exceeds 0.1 mg / cm ² , the lead compound becomes a resistance component and the discharge capacity decreases. Further, the present invention is particularly effective for a manganese dry battery containing no mercury.

[0008]

The mechanism of action of the manganese dry battery of the present invention is as follows.
It is inferred as follows. The lead compound added to the paste material on the separator gradually dissolves in the electrolytic solution to become ions,
Precipitates as metallic lead on the zinc can surface. This coating reduces the dissolution of the zinc can during storage and suppresses an increase in the internal resistance of the battery due to an increase in zinc ions. In addition, the zinc can dissolution reaction during discharge becomes uniform, helping uniform diffusion of discharge products,
It suppresses an increase in internal resistance due to accumulation of zinc ions near the zinc can.

[0009]

An embodiment of the present invention will be described. In FIG.
1 is a negative electrode zinc can to which no mercury is added. Inside the zinc can 1, a separator 2 having a glue layer made of starch, synthetic glue or the like formed on one or both sides is housed such that the glue layer contacts the zinc can 1. The inside thereof is filled with a positive electrode mixture 3 in which a carbon rod 4 is embedded in the center. The positive electrode mixture 3 is formed of a molded body in which manganese dioxide, a conductive agent such as acetylene black or graphite, and an electrolyte such as zinc chloride or ammonium chloride are mixed.

Reference numeral 5 denotes a plastic sealing member, into which a carbon rod 4 is inserted into a central through hole. Reference numeral 6 denotes a metal positive electrode terminal plate fitted to the top of the carbon rod 4, and reference numeral 7 denotes a metal negative electrode terminal plate in contact with the outer bottom of the zinc can 1. Reference numeral 9 denotes a heat-shrinkable and flexible cross-linked polyolefin tube enclosing the outer peripheral wall of the zinc can, and 8 denotes a metal outer can, which has upper and lower ends bent inward to seal the entire battery.

Examples 1 to 3 The separator 2 used in the mercury-free manganese battery of the present invention was prepared by adding lead oxide PbO to a paste paste containing an aqueous solution of polyvinyl alcohol, starch, and a surfactant, followed by thorough stirring. , PbO are uniformly dispersed. Pb at this time
The amount of O added as lead on kraft paper was 0.001,
Three types are prepared so as to be 0.05 and 0.1 mg / cm ² . These pastes are applied to kraft paper and dried to form a separator 2. Using these, R20
Three types of (single 1) type manganese batteries without mercury were prepared.

Comparative Examples 1 to 3 The amount of PbO added to the paste was 0.0005, 0.2
The same operation as in the example was performed except that mg / cm ² and no additive were used, and three types of R20-type manganese dry batteries were prepared. Comparative Example 4 An R20-type manganese dry battery was prepared in the same manner as in Example except that mercury was added to the positive electrode mixture without addition of PbO.

The dry batteries of Examples and Comparative Examples were stored at 45 ° C. for 3 months, and each dry battery was continuously discharged at 300Ω, and the discharge duration up to 0.9 V and the internal resistance at that time were measured. The measurement was performed ten by ten, and the average value was obtained. Table 1 shows the results.

[0014]

[Table 1]

Each of the dry batteries similarly stored at 45 ° C. for 3 months was subjected to one day a day during a continuous discharge of 300Ω.
Pulse discharge of 4 Ω for 5 seconds, 0.9V each
The duration of discharge up to was measured. The measurement was performed ten by ten, and the average value was obtained. Table 2 shows the results.

[0016]

[Table 2]

Although the test results are not shown here, when the battery is discharged without storage, no remarkable difference appears between the embodiment and the comparative example. However, after storage, the effects of the present invention are clear as shown in Tables 1 and 2. Although the embodiment using PbO is shown here, PbCl ₂ , Pb
It has been confirmed that a similar effect can be obtained when (OH) ₂ is used. Note that the present invention can also be applied to a laminated dry battery.

[0018]

As described above, according to the present invention, the increase in the internal resistance of the battery after storage and during light-load and medium-load discharge is suppressed, and manganese without addition of mercury is less reduced in pulse discharge characteristics. Dry batteries can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a manganese dry battery according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Zinc can 2 ... Separator 3 ... Positive electrode mixture 4 ... Carbon rod

Claims (2)

(57) [Claims] 1. A manganese dry battery in which a separator having a glue layer formed on one or both sides is housed such that the glue layer directly contacts the inner surface of a negative electrode zinc can, wherein a lead compound is added to the glue layer. A manganese dry battery. 2. The manganese dry battery according to claim 1, wherein the lead compound is applied to the separator in an amount of 0.001 to 0.1 mg / cm ² as lead.