JPS60165048A - Battery - Google Patents

Abstract

PURPOSE:To improve the reliability in the long-term use such as the preservation, resistance to liquid leakage of a battery by roughing at least a surface of the positive electrode ring that makes contact to a positive electrode. CONSTITUTION:A positive electrode black mix 7 is inserted in a positive electrode case 8 and a positive electrode ring 6 is also inserted therein. Then pressure is applied to the positive electrode black, mix 7 and the positive electrode ring 6 in the positive electrode case 8 by punching. A battery is completed by inserting a separator 5 and impregnant material 4 in this positive electrode side, engaging, a negative electrode side where negative electrode active material 2 is inserted in an assembly sealing plate obtained by assembling a sealing plate 1 in a gasket 3, with the positive electrode side, and curling the end of the case 8 inside. Moreover, the roughness of a surface that makes contact to the positive electrode black mix of the positive electrode ring 6 is set to 1 to 20mum. As a result, the floating of the positive electrode ring 6, the crack of the black mix, defective internal resistance, etc. are eliminated and the long-term reliability such as preservation, resistance to liquid leakage, etc. is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the improvement of batteries, particularly small batteries such as button-shaped and coin-shaped batteries.

Conventional Structure and Problems Small primary batteries have traditionally been used as power sources for wristwatches, cameras, calculators, etc. with low power consumption, and are used for long periods of time. For this reason, among battery characteristics, reliability during long-term use, such as storage stability and leakage, has become particularly important.Hereinafter, the structure of a button-type battery, which is a typical example of a small-sized secondary battery, will be explained.

FIG. 1 shows a cross-sectional view of a button battery.

In the figure, 1 is a sealing plate, 2 is a negative electrode mixture, 3 is a gasket (sealing ring), 4 is an electrolyte impregnated material, 6 is a separator, 6 is a positive electrode ring, 7 is a positive electrode mixture, and 8 is a positive electrode case. .

An example of the order of assembling the positive electrode side of this button type battery will be explained below with reference to FIG.

First, insert the positive electrode mixture (pre-molded) 7 into the positive electrode case 8 as shown in A, then insert the positive electrode ring 6 as shown in B, and then insert the positive electrode mixture 7 and the positive electrode ring in the positive electrode case 8. By applying pressure to 6 with a punch P, the positive electrode side is completed.

However, in such conventional methods, (1) when the positive electrode side is completed, the positive electrode ring 6 may be slightly lifted from the predetermined position as shown in the figure in FIG.

(2) When a battery is assembled using such a positive electrode side, the positive electrode mixture 7 cracks as shown in FIG. 3B, resulting in variations in internal impedance 9 and the leakage resistance is reduced.

Problems such as these were occurring.

OBJECTS OF THE INVENTION The object of the present invention is to eliminate the above-mentioned conventional drawbacks and to improve reliability during long-term use, such as battery storage stability and leakage resistance.

Structure of the Invention In order to achieve this object, the present invention roughens at least the surface of the positive electrode ring that contacts the positive electrode, and reduces the roughness of the surface by 1.
~20μ〃Z.

DESCRIPTION OF EMBODIMENTS An R44 type button battery is shown in FIG. 4 as an embodiment of the present invention.

First, as shown in FIG. 2, the separator 5 and the impregnating material 4 are inserted into the positive electrode side which has been assembled according to the positive electrode side assembly sequence explained in FIG. Fit the negative electrode side (containing electrolyte) 2 inserted as shown in C, and curl the end of the case 8 inward as shown in D to complete the battery (E). Note that the positive electrode ring 6 The roughness of the surface in contact with the positive electrode mixture is 2
If the diameter is 0 μm or more, it is difficult to mold the positive electrode ring, and even if it could be molded, the positive electrode mixture tended to crack more easily.

In order to confirm the effects of the present invention, a button type alkaline manganese battery LR44 (diameter 11.6ffJ height s, 4I
I shoulder). The surface roughness of the positive electrode ring used was 0.5 μm for the conventional product and 12 μm for the product of the present invention. The test method was as follows.

(1) Defective rate due to positive electrode ring lifting 10,000 positive electrode side assemblies were visually inspected.

(2) Internal Resistance Defective Rate After assembling the battery and aging it for one month, it was examined as being 3Ω or more defective. The population was set to 10,070 each.

(3) Storage reliability The battery was left at 60°C for 100 days, and the voltage, internal resistance, and discharge duration under a 15Ω load were investigated. The number of tests was 20 each. It is said that 60'Cl00 days corresponds to 6 years at room temperature.

(4) Leakage resistance After storing the battery at a temperature of 60'C1 and relative humidity of 90% for 3 months and leaving it at room temperature and humidity for 3 days, leakage of electrolyte was prevented by 10%.
Examined under a double microscope. The number of tests was 20 each.

The results were as follows.

Products of the present invention Conventional products (1) Positive electrode ring floating 0% 1.2% Failure rate due to ri (2) Internal resistance failure rate 0% 0.6% (3) Storage reliability (a) Average voltage value 1.540V 1.612V standard deviation 0.002V 0.015V (b) Internal resistance average value 1.89Ω 2.58Ω standard deviation o, 12Ω 1.
o2Ω (C) Average discharge time 1152h 961h Standard deviation 8h 108h (4) Leakage rate 0% 20% Water of the invention As described above, the present invention has problems such as lifting of the positive electrode ring, cracking of the mixture, and poor internal resistance, etc. Good results were obtained, such as eliminating the risk of leakage and improving long-term reliability such as storage stability and leakage resistance, and the effects are significant.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a button battery, and Figures 2A and B. C and D are diagrams showing an example of the procedure for assembling the positive electrode side of the battery, Figure 3 is a cross-sectional view when the positive electrode ring on the positive electrode side is lifted up, and B is a cross-sectional view of the assembled battery. , Figure 4 A, B
, C, D, and E are diagrams showing an example of a procedure for assembling a battery according to an embodiment of the present invention. 6... Positive electrode ring, 7... Positive electrode mixture,
8...Positive electrode case.

Claims (1)

[Claims] A battery in which a positive electrode mixture is contained in a metal positive electrode ring that is inscribed in a metal positive electrode case having an open end and has an inverted cross-sectional shape and has a flat portion extending inward at the upper end. A battery characterized in that at least a surface in contact with a positive electrode is roughened, and the roughness of the surface is 1 to 20 μ772.