JPH03226970A - Button alkaline battery - Google Patents

Abstract

PURPOSE:To enhance battery characteristics by deforming the vertical flange end portion of a positive electrode ring by means of secondary molding so as to make the end portion to abut on the bottom surface of the inside of a positive electrode case. CONSTITUTION:The vertical flange end portion 3a of a positive electrode ring 3 is deformed by secondary molding and made to abut on the bottom surface of the inside of a positive electrode case 2. In such a battery, pressure generated by expansion of a negative electrode material 5 is exerted on the surface of a softened positive electrode mix 1 and the positive electrode mix 1 starts to subside at the period just before a discharge voltage leads to a finishing voltage as discharge progresses, but since the vertical flange end portion 3a of the positive electrode ring 3 presses the bottom surface of the inside of the positive electrode case 2 to securely support the outer peripheral portion of a positive electrode mix tablet, reduced metal in the positive electrode mix cannot enter a negative electrode container 6. Thereby a short circuit inside the battery and shortening of the duration of battery discharge are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an alkaline manganese battery having a button-shaped shape;
It relates to button-type alkaline batteries such as mercury batteries and silver oxide batteries.

Conventional technology When constructing the positive electrode body of a button-type alkaline battery, as shown in FIG. 2(a), the positive electrode mixture 1 is formed into a tablet shape by rough molding (hereinafter referred to as primary molding) and inserted into the positive electrode case 2. After fitting the positive electrode ring 3 having an inverted cross section onto the top surface of the tablet, the tablet was formed by pressure molding (hereinafter referred to as secondary molding) so that the top surface was uniform. Vertical flange tip 3a of positive electrode ring 3 after secondary molding
As shown in FIG. 2(a), the inner bottom surface of the positive electrode ring is not in contact with the inner bottom surface of the positive electrode case 2, or as shown in FIG. The tip part was not deformed (they were in contact with each other).As shown in Figure 2, the structure of the battery is as follows: the positive electrode body (1+2+3) is stacked with the separator 8 on the bottom and the impregnating material 4 on the top. Place the sheets,
A negative electrode container 6 containing a gelled zinc negative electrode 5 containing an alkaline electrolyte, a negative electrode active material, etc. (an insulating caskerat 7 is adhered to the outer periphery of the negative electrode container 6) is placed on top of the impregnated material 4, and a positive electrode is formed. (e) The periphery of the insulating gasket 7 was tightened around the opening edge of the case 2. Figure 2 (b) 2 is Figure 2 (b)
) shows a battery using a positive electrode body.

Problems to be Solved by the Invention Button-type alkaline batteries are designed to be filled with a larger amount of the gelled zinc negative electrode in order to increase the electrical capacity. 9
It occupied 9% of the filling volume. In this button-type alkaline battery, as discharge progresses, the gelled zinc negative electrode 5 expands inside the battery, as shown in FIG.
It advances beyond 100% of the internal volume of the insulating gasket 7.

Therefore, the impregnating material 4 and the separator 8 pressurize the surface of the positive electrode mixture 1. At the same time, the metal oxide (in the case of alkaline manganese batteries, it is manganese dioxide, and in the case of mercury batteries and silver oxide batteries, it is mercury oxide and silver oxide, respectively), which is the positive electrode active material in the positive electrode mixture 1, is reduced. .

As a result, the pressurization from the negative electrode side causes the reduced metal in the positive electrode mixture 1 to flow upward (toward the negative electrode side). At this time, since it is the final stage of discharge, the positive electrode mixture has softened and the vertical flange tip 3a of the positive electrode ring is not in contact with the bottom of the positive electrode case 2, so the positive electrode mixture sinks to the ground and the separator 8
This reduces the adhesion of the horizontal flange of the positive electrode ring. Therefore, the flow is promoted. The metal flows upward through a path between the inner peripheral part of the positive electrode case 2 and the outer peripheral part of the vertical flange of the positive electrode ring 3 which is in contact with the inner peripheral part of the positive electrode case 2. Furthermore, an insulating gasket 7 which is the outer periphery of the negative electrode container
The impregnated material 4 was in contact with the gelled zinc negative electrode 5 by passing between the bottom of the impregnated material 4 and the upper surface of the outer peripheral part of the impregnated material 4 that was in contact with the bottom of the impregnated material 4 . Therefore, there was a problem that an internal short circuit occurred and the discharge duration of the battery was shortened to about 80 to 90% (e) of that of a normal battery. Figure 2 In all cases, the tip of the vertical flange of the positive electrode ring is touching the curved surface on the outer periphery of the inside bottom of the positive electrode case, but it is not pressing on that curved surface, so it does not completely support the positive electrode mixture ground. do not have. Therefore, the discharge duration was about 85 to 95% of the normal product, which was still not perfect.

In view of the above problems, the present invention provides a button-type alkaline battery that does not deteriorate the discharge characteristics of the battery even when the negative electrode container is filled with gelled zinc negative electrode to nearly 100% volume.

Means for Solving the Problems To achieve this object, the present invention provides a button-type alkaline battery in which the vertical flange tip of the positive electrode ring is deformed by secondary molding and comes into contact with the inner bottom surface of the positive electrode case.

Function: With this type of battery, as discharge progresses and just before the discharge voltage reaches the final voltage, pressure due to the expansion of the negative electrode material is applied to the softened surface of the positive electrode mixture, and even if the positive electrode mixture begins to sink to the ground. , the reduced metal in the positive electrode mixture is transferred into the negative electrode container because the vertical flange tip of the positive electrode ring presses against the inner bottom surface of the positive electrode case and strongly supports the outer periphery of the positive electrode base tablet. Therefore, the above-mentioned problems of internal short circuit and short battery discharge duration are solved.

Embodiment Hereinafter, an embodiment of the present invention will be explained with reference to FIG. The positive electrode body is constructed by secondary molding so that the positive electrode body is formed. Then, two sheets with separator 8 on the lower side and impregnating material 4 on the upper side are placed on the upper surface, and a negative electrode container 6 (its outer periphery An insulating gasket 7 is glued to the battery (with a height of 5.
, 4 mm, and an outer diameter of 11.6 mm.This example is a mercury battery in which the active material in the positive electrode mixture is mercury oxide. 〉

Among these, the feature of the present invention lies in the position of the vertical flange tip 3a of the positive electrode ring, which is deformed by secondary molding and comes into contact with the inner bottom surface of the positive electrode case 2, as shown in FIGS. are in contact with each other. In other words, just before the secondary molding, the tip 3a retains its original shape (linear shape) and does not touch or almost touches the inner bottom surface of the positive electrode case, and the pressure from the secondary molding causes the tip 3a to It is bent or compressed and touches the bottom surface.

In addition, when filling a predetermined volume of cathode mix with a predetermined filling weight of the cathode mix, there may be cases where volume loss cannot be tolerated due to the pressurizing capacity of the molding machine or mix density characteristics, or when the cathode ring is horizontal. 7. If you want to hold the lunge part more horizontally, you can do it as shown in (b) and at the end of Figure 1. That is, the positive electrode case 9 already has a recess 9a on the outer periphery of the inner bottom surface (see FIG. 1(C)). And just before secondary molding,
The tip portion 3a, which has not entered the recess 9a and has been floating upward, is inserted into the recess 9a by secondary molding, expands the recess 9a, and is also compressed and abuts like a rivet joint.

In the latter case, compared to the former, it is possible to secure a larger volume of positive electrode mixture, and since the drag force immediately after secondary molding is transmitted more horizontally to the upper surface, the horizontal flange part of the positive electrode ring can be held more horizontally.

A button-type mercury battery according to the present invention (two types) as described above,
Assemble 20 batteries of the same type and two conventional types, and after the battery is completed, load resistance 3. By OkΩ,
As a result of measuring the continuous discharge duration until the discharge voltage dropped to 0.9V, the product of the present invention had remarkable effects as shown in the table below. The four types of batteries in the table below have a charging capacity (
The electric capacity of the negative electrode active material is 3. It is assembled so that the variation in continuous discharge duration of OkΩ is within 2 hours.

(Margins below) When the product of the present invention was disassembled after the above test, it was found that, unlike conventional products, the positive electrode ring has a strong ground support effect on the outer periphery of the positive electrode mixture tablet, and The metallic mercury was trapped under the separator, preventing it from penetrating onto the insulating gasket of the negative electrode container.

Incidentally, as a result of conducting the above experiments on alkaline batteries other than mercury batteries, such as alkaline manganese batteries and silver oxide batteries of the same size, as well as other sizes of these three battery systems, despite the differences in size and battery system, It was confirmed that the discharge characteristics of all the products of the present invention were improved.

Effects of the Invention As described above, according to the present invention, the tip of the vertical flange of the positive electrode ring is deformed by secondary molding and comes into contact with the inner bottom surface of the positive electrode case, thereby improving battery characteristics.

[Brief explanation of drawings]

FIG. 1(C) is a half-sectional view showing a battery configured using the positive electrode case 9 in an enlarged cross-section of the bottom of the positive electrode case 9 in the present invention. 1... Positive electrode mixture,
2... Positive electrode case, 3... Positive electrode ring, 3a... Vertical flange tip of 3, 4...
... Impregnation material, 5 ... Gel-like zinc negative electrode, 6 ...
...Negative electrode container, 7...Insulating gasket, 8
... Separator, 9 ... Positive electrode case with recess on inner bottom outer periphery, 9a ... Recessed part of 9.

Claims (2)

[Claims] (1) Insert the positive electrode mixture into a tablet shape by rough molding (primary molding) into the positive electrode case, fit a positive electrode ring with an inverted L-shaped cross section onto the top surface of the tablet, and then make sure that the top surface is uniform. A button-type alkaline battery whose positive electrode body is formed by pressure molding (secondary molding), wherein the vertical flange tip of the positive electrode ring is deformed by the secondary molding and comes into contact with the inner bottom surface of the positive electrode case. A button-type alkaline battery featuring: (2) The button-type alkaline battery according to claim 1, characterized in that a recess is provided in the outer periphery of the inner bottom surface of the positive electrode case against which the vertical flange tip of the positive electrode ring comes into contact.