JPS58131653A - Enclosed cell - Google Patents

Abstract

PURPOSE:To improve leakproof of liquid and decrease internal resistance of a cell, by tilting the upper periphery of a positive electrode molded under pressure to a cell case and preventing deformation of a seal plate at sealing. CONSTITUTION:A positive electrode compound 2 is formed by pressure molding of mixed powder of silver oxide and graphite or the like, and an alkali electrolyte is impregnated to an electrolyte impregnated material 4. A negative electrode compound 5 consists of mixed powder of hardened zinc and viscousness increasing agent or the like. Insulating seal packings 6, 6' of ring shaped section consist of synthetic rubber with excellent elasticity and softness or synthetic resin with excellent ageing resistance and mechanical strength. At pressure molding, a slope of 5-15 deg. is provided in a part corresponding to a bottom face of the seal packing in the upper periphery of a molded positive electrode. Because of reaction of a sloped surface against force which tends to internally deform a seal plate and seal packing when sealed, the seal plate and the seal packing are not deformed, and a sealing condition as designed can be realized.

Description

Detailed Description of the Invention The present invention provides liquid-tight sealing of the opening of a battery case containing a power generation element, such as a silver oxide battery, a mercury battery, a lithium battery, etc., with a sealing plate via an insulating sealant. Regarding sealed batteries, the present invention aims to prevent deformation of the sealing plate during sealing by improving the shape of the molded positive electrode, eliminate incomplete sealing caused by deformation of the sealing plate, and improve leakage resistance. The purpose of this is to reduce the internal resistance of the battery by eliminating the sagging of the electrolyte-impregnated material and the separator due to the deformation of the sealing plate.

Hereinafter, the present invention will be explained with reference to drawings showing embodiments thereof.

Is Figure 1 conventional? 1 is a schematic cross-sectional view of a tan-type silver oxide battery.

Figure 2 shows a molded positive electrode according to the present invention. This is a schematic cross-sectional view of a tan-type silver oxide battery. Ol is a bottomed cylindrical gold case, 2 is a positive electrode mixture placed at the inner bottom of case 1, and a mixed powder of silver oxide, graphite, etc. is press-molded. This is what I did. 3 is a separator placed on top of the positive electrode mixture 2, and 4 is an electrolyte-impregnated material placed on the soil of the separator 3, which is impregnated with an alkaline electrolyte. Reference numeral 5 denotes a negative electrode mixture disposed on the impregnating material 4, which is made of a mixed powder of frozen zinc, a thickener, and the like. 6. 6' is a ring-shaped insulating seal with a cross-sectional shape, and has elasticity,
Made of synthetic rubber with excellent flexibility or synthetic resin with excellent aging resistance and mechanical strength. Reference numeral 7 denotes a single metal sealing plate in the shape of an inverted dish that closes the opening of the case l with a sealing plate or a king 6 interposed therebetween, and a bulge 7a and a U-shaped 7b are formed on the periphery of the plate. It is set up. Note that both FIG. 1 and FIG. 2 are examples in which positive electrode rings 8, 8' are used.

In the case of a conventional battery (Fig. 1), when sealing the battery VC1
The horizontal component of the th11 force is directed toward the center of the battery as shown by arrow A, and the sealing plate 7 is aligned with the sealing A? It transforms into the inner part with the locking 6. As a result, the Ft shrinkage ratio of the sealing tube and the sealing did not match the design, and an ideal sealing condition could not be obtained, causing liquid leakage. In addition, as the sealing plate 7 and the sealing/grooving 6 are deformed inward, the center/arm plate 3 and the electrolyte impregnating agent 4 placed on the positive electrode mixture are also pushed toward the center, causing them to fall into the positive electrode mixture. The wrinkles formed at the top created air spaces, which increased the battery's internal resistance.

On the other hand, in the case of the battery of the present invention (Fig. 2), the part corresponding to the lower surface of the sealing/matting on the upper outer periphery of the molded positive electrode is 5° to 15° (Fig. θ inside
). Due to the force that tries to deform the sealing plate, sealing, and sealing inward, due to the reaction of the above-mentioned slope, the sealing plate, sealing, and sealing do not deform and seal as designed. The condition was realized and the leakage resistance was improved.

In addition, the sagging of the separator and impregnating agent could be eliminated, and since there was no air layer, the internal resistance of the battery could be lowered.

Table 1 shows 100 each of silver oxide battery A according to the present invention and silver oxide battery B using a molded positive electrode with a flat upper surface of the conventional width at a temperature of 45°C and a relative humidity of 80 to 90°C. The results of a comparison of the number of batteries that caused leakage when stored in an atmosphere of

Moreover, FIG. 3 shows the change over time in the average value of internal resistance of 50 batteries each of batteries A and B.

As described above, according to the present invention, a sealed battery with excellent leakage resistance (ζ) and low internal resistance can be obtained.

[Brief explanation of drawings]

FIG. 1 is an abbreviated side view of a battery using a conventional molded positive electrode, FIG. 2 is a schematic cross-sectional view of a battery using a molded positive electrode according to the present invention, and FIG. 3 is an internal view of a battery using a conventional molded positive electrode. This is a graph showing the change in resistance over time. l...Battery case, 2.2'...Positive electrode mixture, 3...
・SeiJ? Rator, 4... Electrolyte impregnated material, 5... Negative electrode mixture, 6°6'... Sealing flat, King, 7... Sealing plate, 7a... Sealing plate bulge, 7b... ...Sealing plate rising part, 8.8'...Positive electrode ring. Figure 1 Figure 2

Claims (1)

[Claims] A battery case, a sealing plate that seals the opening of this case,
and a sealed battery in which the power generation element is sealed by a sealing/gucking having a cross-sectional shape interposed between the battery case and the sealing plate, and the upper outer periphery of a molded positive electrode formed by h0 pressure molding on the battery case. A sealed battery characterized by having an inclined angle.