JPS6077353A - Silver oxide secondary battery - Google Patents

Abstract

PURPOSE:To increase the storage performance of a silver oxide secondary battery and improve its electric characteristics such as discharge capacity and open circuit voltage by using as a separator a laminar body containing a radiational graft polymerization film. CONSTITUTION:In a button-type battery having a negative electrode 16 made of gel-like zinc and a positive electrode 18 principally consisting of silver oxide, a separator 40 consists of a laminar layer formed by stacking two pieces of cellophane 34 over a triple-layered laminar layer 30 formed by placing a cellophane film 34 between radiational graft polymerization films 32 and 32. The films 32 and 32 are formed by graft polymerizing a synthetic film base such as polyethylene with hydrophilic radicals of a compound such as acrylic acid or methacrylic acid by means of radiation. By the means mentioned above, the silver ion resistance of the battery is greatly increased without much increasing the thickness of the separator and without decreasing the conductivity between the positive and the negative electrodes. Accordingly, it is possible to increase the storage performance widely without sacrificing any electric characteristics such as discharge capacity and internal resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silver oxide secondary battery, and particularly to a secondary battery using silver oxide as an anode active material.

A battery using silver oxide as the positive electrode active material can be used repeatedly not only as a secondary battery but also as a secondary battery. However, when used as a secondary battery, it must be durable enough to withstand repeated charging and discharging. In particular, silver oxide as an anode active material has a very strong oxidizing power, and therefore the hyaluronic acid interposed between the anode and the cathode tends to deteriorate.

In this type of conventional silver oxide battery, the separator used is a multilayer structure in which, for example, several layers of porous polypropylene film and cellophane are laminated together. However, although porous polypropylene film has relatively good ionic properties and low electrical resistance, it lacks the ability to block and cover silver ions, and during long-term storage, oxidation on the anode side occurs. It had the disadvantage that it deteriorated due to the influence of silver. For this reason, sufficient storage performance could not be obtained.

Moreover, it could not withstand repeated charging and discharging for 61 minutes, and therefore could not be particularly suitable as a silver oxide secondary battery.

Here, if the purpose is simply to improve the storage performance of the inverter, it is sufficient to increase the number of layers of the lever. However, as the number of layers increases, the thickness of the separator increases, which reduces the effective power generation capacity within the battery and reduces the discharge capacity, and also impairs the ionic conductivity between the anode and cathode, resulting in increased internal resistance etc. characteristics will deteriorate.

This invention was made in view of the above problems, and its purpose is to prevent silver ions without increasing the thickness of the separator or reducing the conductivity between the anode and cathode. To provide a silver oxide secondary battery in which storage performance can be significantly improved without sacrificing electric characteristics such as discharge capacity ωJ3 and resistance. It is in.

In order to achieve the above object, the present invention provides a secondary battery using silver oxide as an anode active material, a three-layer laminate body made of cellophane sandwiched between polymeric films as shown in radiation graph 1, and furthermore, It is characterized in that a multilayer body made by laminating two layers of cellophane on a three-phase laminate body is used as a separator.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of a silver oxide secondary battery according to the present invention.

The silver oxide secondary battery shown in the figure has a button-shaped battery case 1.
0 is loaded with power generation elements 20 formed in layers.

The battery case 10 includes a metal anode can 1 that also serves as an anode terminal.
4. Metal shade 4FA terminal 12 that forms part of the case
, and is made up of 4R gaskets 15).

The power generating element 20 is constructed of a JR structure including a cathode 16 made of zinc in the form of a J-glue, an anode 18 mainly made of silver oxide, and a pallet 40 impregnated with an alkaline electrolyte.

Here, as shown in a partially enlarged view in FIG. 1, the Hibarator 401 has three layers of 11i Kensen Gusifu 1 and cellophane 34 sandwiched between polymeric films 32. It is constituted by a multilayer body made by layering two layers of cellophane 34 on a three-layer laminate body 30.

Here, the three-layer laminate body 30 is laminated in advance separately from the two sheets of cellophane 34, 34,
The radiation graft polymerized films 32 and 32 forming the layers on both sides are made by polymerizing hydrophilic groups such as acrylic acid and methacrylic acid onto a basic synthetic film such as polyethylene using radiation. The materials used in this example have a graph 1 ratio of 50 to 80% and a relatively low degree of polymerization of hydrophilic groups, such as "permion" (p
ermion) S C113 (product name, RΔI R
A three-layer laminate product such as e5earch Corporation) J is used. The lever regulator 40 is obtained by stacking two sheets of Hirohan on such a three-layer laminate product.

Now, we will compare the storage performance of a silver oxide battery assembled using the lever regulator 40 configured as described above and a silver oxide battery assembled using a conventional porous polypropylene film and a cellophane evaporator. When I looked at it, I found 100 results as shown in Figure 2. That is, when we conducted a 40-day storage test under the storage condition of 60°C, we found that the decrease in open circuit voltage of the former battery A was significantly smaller than that of the latter battery B. :.

In addition, when using the above three-layer laminate 30, when changing the number of cellophane sheets added thereto,
As shown in FIG. 3, it was found that when the number of sheets was two, excellent results were obtained in both discharge capacity d5 and open circuit voltage residual rate. That is, if the number of cellophane sheets is less than h ~ 2 sheets, the open circuit voltage residual rate will decrease, and if it is more than 152 sheets, the thickness of the separator will increase and the discharge capacity will gradually decrease. It arises. Therefore, the above three-layer laminate body 3
It turns out that the number of cellophane sheets added to zero must be two.

As described above, the silver oxide secondary battery according to the present invention has a three-layer laminate as a base consisting of cellophane sandwiched between radiation-grafted polymer films, and further has two sheets of cellophane (11) stacked on the three-layer laminate. By using the multilayer body as a separator, storage performance can be improved, and electrical characteristics such as discharge capacity and open circuit voltage can also be improved. In addition, due to these, sufficient durability as a secondary battery can be obtained.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a primary embodiment of a silver oxide secondary battery according to the present invention, Figure 2 is a diagram showing the difference in storage performance between the battery according to this invention and conventional battery B, and Figure 3 is a diagram showing the difference in storage performance between the battery according to the present invention and conventional battery B. It is a figure which shows the relationship between the number of sheets, discharge capacity, and open circuit voltage residual rate. 10...Battery case 12...Cathode terminal 14...Anode can 15...Sealing gaskets 1-16...Several types 18. ...Anode 20 mainly composed of silver oxide...
...Power generation element 30...Three-layer laminate body 32
...Radiation graft polymerized film 34...Cellophane 40...Separator patent applicant Fuji Electrochemical Co., Ltd.

Claims (1)

[Claims] (1) Cellophane sandwiched between radiation-grafted polymer films 3
A silver oxide secondary battery characterized in that a layer laminate is used as a base, and a multilayer body made by stacking two sheets of cellophane on the three-layer laminate is used as a separator. (2. A silver oxide secondary battery according to claim (1), characterized in that the three-layer laminate is placed on the anode side, and the two sheets of cellophane are placed on the cathode side.