JPH0757731A - Alkaline battery - Google Patents

Abstract

PURPOSE:To stabilize discharge capacity by preventing clogging of a nozzle of a gel filling machine by using an almost spherical mercury-less zinc particle as a gel-like negative electrode active substance, and reducing dispersion of a filling quantity. CONSTITUTION:A ratio of a long diameter to a short diameter of a zinc powder particle and the particle size are selected in a prescribed range. This is mixed in alkaline aqueous solution, and a gel-like negative electrode active substance 3 is created. A positive electrode 1 is filled in a positive electrode case 2, and a separator 5 and an electrolyte holding material 6 are placed on an upper surface. An insulating packing 7 is fitted around a sealing plate 4, and the negative electrode active substance 3 obtained by mixing an almost spherical Zn powder particle 8 and gel-like electrolyte 9 together, is filled by equivalency inside of the sealing plate 4 by a gel filling machine. A positive electrode body and a negative electrode body are fitted to/combined with each other, and the upper end of the positive electrode case is bent inside and is sealed. In this constitution, clogging of a filling nozzle is not caused, and weight dispersion of the filled negative electrode active substance is reduced, and dispersion of discharge maintaining time is also reduced, and a stable-quality battery can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a negative electrode active material for alkaline batteries.

[0002]

2. Description of the Related Art In recent years, by using zinc powder particles containing at least one of lead, aluminum, indium, gallium, and calcium in zinc powder, it is possible to obtain a negative electrode acting substance without adding mercury. It has become possible to incorporate it in batteries. However, in the case of zinc fluoridation, the particles of the zinc powder are sharpened in the process of hydration, but in the case of unfluorinated zinc, the particles maintain the needle-like shape of the raw powder, as shown in Fig. 2. The needle-shaped unremoved zinc powder particles 18 are mixed with an alkaline aqueous solution 19 having a predetermined concentration in which a predetermined amount of polyacrylic acid and zinc oxide are dissolved, and the gel-like substance is charged into the battery as the negative electrode active substance 13. Was.

[0003]

However, conventionally, since the particle shape of the unconstrained zinc remains acicular, the friction between zinc particles is large and the fluidity is poor. For this reason, when the battery is filled with the gelled negative electrode active substance, particles are cross-linked at the tip of the filling nozzle, which causes a problem that the nozzle is easily clogged. Further, the filled negative electrode active material also has a large variation in weight, resulting in a large variation in discharge duration during use.

According to the present invention, by using the non-defining zinc powder particles having a substantially spherical shape, a predetermined amount of polyacrylic acid and zinc oxide are mixed with an alkaline aqueous solution of a predetermined concentration to form a gel. When assembling things into a battery with a gel filling machine, friction of zinc particles is reduced, fluidity is also good, there is no problem such as clogging at the tip of the nozzle, and there is little variation in discharge duration time. The purpose is to provide a battery.

[0005]

In order to solve such problems, the present invention provides a zinc powder which contains at least one of lead, aluminum, indium, bismuth, gallium and calcium. The particles having a substantially spherical shape are incorporated in a battery. Specifically, in the present invention, the ratio of major diameter / minor diameter of the zinc powder particles is 1.
0 to 2.0 and particle size distribution of 40 to 150 mes
It is an alkaline battery that uses a substance classified into h as a negative electrode acting substance.

[0006]

As described above, by using the non-alloyed zinc powder particles having a substantially spherical shape, the friction between the particles can be reduced, and the gelled negative electrode active material can be used as a negative electrode terminal. When filling the double-sided sealing plate, the problem that the gel is clogged at the tip of the filling nozzle no longer occurs. Further, the filled negative electrode active material has little variation in weight, and it is possible to supply a battery of stable quality with little variation in discharge duration.

The spherical zinc has a particle major diameter / minor diameter ratio of 1.0 to 2.0. When the ratio exceeds 2.0, gel clogging at the tip of the nozzle of the gel filling machine is complete. This is because the particle size distribution is 40 to 150 me.
If sh is 40 mesh or less, the particles are large, and therefore, sufficient effect cannot be obtained in weight variation of the gel. This is because the problem of gel clogging occurs.

[0008]

EXAMPLES The invention product and the comparative product will be described. The ratio of major diameter / minor diameter of zinc powder particles is 1.0, 2.0, 3.0,
A particle size of 80 to 120 mesh was prepared. These were mixed with an alkaline aqueous solution having a predetermined concentration in which polyacrylic acid and zinc oxide were dissolved to prepare a gelled negative electrode active substance 3 shown in FIG. This is 5,000 using a gel filling machine.
The nozzle was clogged once, and the gel filling amount of n = 10 was measured every 1000 times. SR at the same time using this filling machine
A 1130 W alkaline battery was prototyped and discharged. For comparison, a negative electrode active material 13 of FIG. 2 was prepared using needle-shaped zinc powder particles 18 having the above ratio of 5 to 7, and the same experiment was performed. The results are shown in Table 1.

As shown in FIG. 3, in the SR1130W alkaline battery, the positive electrode case 2 is first filled with the positive electrode 1, and the separator 5 and the electrolytic solution holding material 6 are placed on the upper surface thereof. On the other hand, an insulating packing 7 is fitted around the sealing plate 4, and the negative electrode active substance 3 of FIG. 1 obtained by mixing the spherical zinc powder particles 8 and the gel electrolyte 9 inside the sealing plate 4 is gel-filled. Fill equal amount by machine. The positive electrode body and the negative electrode body are fitted and combined with each other, and the upper end of the positive electrode case is bent inward and sealed.
These alkaline batteries were discharged and the capacity was measured.

[0010]

[Table 1]

In order to know the optimum particle size distribution, the particle size distributions of zinc particles having major and minor diameters of 1.0 and 2.0 are -40 mesh and 40-80, respectively.
mesh, 80-120 mesh, 120-150me
The same experiment was performed for sh, 150 mesh-. The results are shown in Table 2.

[0012]

[Table 2]

As shown in Tables 1 and 2, when zinc particles having a major diameter / minor diameter ratio of 1.0 to 2.0 are used, gel clogging does not occur at the nozzle tip of the gel filling machine, and Regarding the particle size distribution, it is possible to reduce the variation in the capacity of the battery by using the one classified into 40 to 150 mesh.

[0014]

EFFECTS OF THE INVENTION According to the present invention, the gel-filling machine is provided by making the particles of the unremoved zinc powder have a major diameter / minor diameter ratio of 1.0 to 2.0 and a particle size distribution of 40 to 150 mesh. It is possible to prevent the nozzle from being clogged, make the filling amount of the negative electrode active material uniform, and obtain an alkaline battery with a small variation in discharge capacity.

[Brief description of drawings]

FIG. 1 is an enlarged view of a gelled negative electrode active material using substantially spherical zinc powder particles according to the present invention.

FIG. 2 is an enlarged view of a gelled negative electrode active substance using conventional acicular zinc powder particles as a comparative product.

FIG. 3 is a cross-sectional view of an alkaline battery using the gelled negative electrode active material of the present invention.

[Explanation of symbols]

 3 Negative Electrode Working Material 8 Zinc Powder Particles 9 Gel Electrolyte 18 Zinc Powder Particles

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Takagishi 3-4-10 Minami-Shinagawa, Shinagawa-ku, Tokyo Inside Toshiba Battery Co., Ltd.

Claims (1)

[Claims] 1. In an alkaline battery in which unhydrogenated zinc powder particles containing at least one or more of lead, aluminum, indium, bismuth, gallium, and calcium are used as a negative electrode active material, the long diameter / short diameter of the zinc powder particles. Is 1.0 to 2.0, and the powder particle size distribution is 40 to
Alkaline battery characterized by being 150 mesh.