JPH0548365Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a cylindrical alkaline battery, and particularly relates to structural improvements thereof.

Conventionally, a cylindrical alkaline battery having a structure shown in FIG. 1 is known. In this alkaline battery, a power generation element is loaded into a bottomed cylindrical metal anode can 10, and the open end of the anode can 10 is sealed with a cathode terminal 12 and an electrically insulating gasket 14. The power generation element is a cathode 2 made of gelled zinc.
0 and separator 1 impregnated with alkaline electrolyte
8 and an anode 16 whose active material is manganese dioxide. The separator 18 is made of a nonwoven fabric such as vinylon or polypropylene,
It is formed into a bag-like cylindrical shape. A cathode 20 is loaded into the separator 18, and a current collector rod 2 electrically connected to the cathode terminal 12 is placed inside the cathode 20.
2 has been inserted. The cylindrical separator 18 is arranged concentrically at the center of the anode can 10, and the anode 16 is placed around it.

A metal jacket 26 is attached to the outer periphery of the anode can 10 via an electrically insulating middle cylinder 24.
is installed. Further, the bottom surface of the anode can 10 is a flat surface as shown in the figure, and an anode terminal 30 having a shape having a convex portion projecting outward is attached to this portion. This anode terminal 30 is fixed by a curled caulked portion at the lower end portion of the exterior body 26 with an electrically insulating washer 28 interposed therebetween.

Note that the lower end portion of the separator 18 is closed to form a bottom portion 18a. This closed bottom 18
a is formed by heat-sealing one end of the separator 18.

Conventional alkaline batteries configured in this manner have the following problems.

Since the bottom surface of the anode can 10 is flat and the convex anode terminal 30, which is a separate component, is attached to this part while being electrically connected, there is a problem that the number of parts is large and assembly is troublesome. In addition, anode can 10
The contact resistance between the electrode terminal 30 and the anode terminal 30 cannot be ignored. Furthermore, there is a wasted space between the anode terminal 30 and the anode can 10, which is indicated by the symbol a and is not involved in the power generation action at all.

Further, the bottom portion 18a of the separator 18 closed by heat fusion does not have a flat surface like the bottom portion of the anode can 10, but has a convex curved shape as shown in the figure. Therefore, a space b is created between the closed bottom portion 18a and the pressure-molded anode 16 in the peripheral portion thereof. This space b also becomes a wasted space that does not contribute to power generation at all.

More importantly, when the ends of the separator 18 are closed by heat fusion, the properties of the heated portion change, and the ionic conductivity of this portion is significantly reduced. That is, the area around the closed bottom portion 18a of the separator 18 has extremely poor ionic conductivity. In the conventional battery shown in FIG. 1, a portion of the separator 18 with poor ionic conductivity is interposed between the anode 16 and the cathode 20, where an active discharge reaction should normally take place, and significantly inhibits a good discharge reaction. ing.

This idea was devised in view of the conventional problems mentioned above, and its purpose was to reduce the number of parts by eliminating the separate anode terminal, and to increase the effective capacity by eliminating wasted space inside the battery. let me,
Another object of the present invention is to provide a cylindrical alkaline battery in which the adverse effects of a portion of the separator whose ion conductivity has deteriorated due to heat fusion are minimized.

In order to achieve the above object, this invention integrally forms a convex terminal part with a two-step shape protruding outward at the center of the bottom surface of the anode can, and an internal space of this convex terminal part. It is characterized by a curved closed bottom portion of a separator filled with a cathode active material.

Hereinafter, preferred embodiments of this invention will be described in detail based on the drawings.

Figure 2 shows a cylindrical alkaline battery to which this invention is applied.

This alkaline battery has a bottomed cylindrical anode can 10
A power generating element is loaded inside the anode can 10, the open end of the anode can 10 is sealed with a cathode terminal 12 and a gasket 14, and the outer periphery of the anode can 10 is covered with an exterior body 26 through an inner cylinder 24. The basic structure of the battery is the same as that of the conventional battery shown in FIG. The internal power generation elements are also the same as before. Furthermore, the end of the separator 18 is closed by heat fusion, and the closed end 18a has a convex curved shape.
It is also the same as the conventional one in that it is formed.

In the alkaline battery of this invention, there is no anode terminal 30 (FIG. 1), which was a separate component in the prior art. The anode can 10 itself also serves as an anode terminal. for that,
The bottom surface of the anode can 10 is not flat, but as shown in FIG. 2, a convex terminal portion 10a projecting outward is formed at the center of the bottom surface. In this embodiment, the convex terminal portion 10a is formed in the shape of two steps.
Of course, this convex terminal portion 10a is integrally formed at the same time as the anode can 10 is press-molded.

Then, the internal space portion c of the convex terminal portion 10a
The closed bottom portion 18a of the separator 18 filled with the cathode 20 is fitted into the bottom portion 18a. As a result, as can be easily understood by comparing Figures 1 and 2,
In the battery of this invention, the wasted spaces a and b in conventional batteries are almost eliminated, leaving only a very small space in this area. What is particularly noteworthy is that
The closed bottom portion 18a of the separator 18, whose ionic conductivity has significantly deteriorated due to heat fusion, fits into the internal space of the convex terminal portion 10a. Therefore, in the portion sandwiched between the anode 16 and the cathode 20, there are almost no portions of the separator 18 where the ionic conductivity has deteriorated.

Therefore, in the alkaline battery according to this invention, since the anode holder, which is a separate part, is eliminated, the number of parts is reduced, assembly is simplified, and the problem of contact resistance between the anode can and the anode terminal is eliminated. Furthermore, since there is no wasted space within the battery, the capacity of the active material can be increased. Further, since the influence of the portions of the separator 18 whose ionic conductivity has deteriorated due to thermal fusion is almost eliminated, the utilization rate of the active material is improved. These things improve the discharge performance of the battery.

As explained in detail above, according to this invention, it is possible to realize an excellent alkaline battery with a simpler and cheaper structure and better discharge performance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional alkaline battery, and FIG. 2 is a sectional view of an alkaline battery according to an embodiment of this invention. 10... Anode can, 10a... Convex terminal part, 12
... cathode terminal, 14 ... gasket, 16 ... anode, 18 ... separator, 18a ... closed bottom,
20... cathode, 22... current collecting rod.

Claims (1)

[Scope of utility model registration request] In a cylindrical alkaline battery in which a power generation element including a cylindrical separator having a bottom closed by heat fusion is sealed concentrically in a bottomed cylindrical anode can, the bottom surface of the anode can A two-step convex terminal part protruding outward is integrally formed in the center of the terminal part, and in the internal space of this convex terminal part,
An alkaline battery characterized in that a curved closed bottom portion of the separator filled with a cathode active material is fitted therein.