JPS5821781B2 - Manufacturing method for button batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a button type battery, particularly an alkaline battery, and provides a battery with excellent leakage resistance and discharge performance.

In conventional button batteries, after filling a cathode sealing plate with a cathode material mainly made of zinc hydrate active material that holds an electrolyte, an electrolyte holding layer and an isolation layer are placed to cover the cathode material. Then, an anode container filled with an anode mixture using silver oxide, manganese dioxide, nickel hydroxide, mercury oxide, etc. as an active material is fitted and assembled, and the opening of the anode container is bent inward and tightened. It was sealed to form a battery.

However, in the conventional method described above, during battery assembly, the electrolyte holding layer swells and moves due to electrolyte absorption, or the isolation layer is deformed, moved, or damaged, causing fine particles of the anode or cathode to move toward the opposite electrode. This caused a short circuit due to contact with the battery, causing self-discharge, and a decrease in capacity due to electrolyte leakage and insufficient electrolyte volume.

In order to prevent such defects, a separator made by bonding an electrolyte holding layer and an isolation layer is adhered to the inner wall of the insulating backing using an adhesive, and this is fitted to the periphery of the cathode sealing plate. This was then combined with an anode container filled with an anode mixture to form a battery.

Although the above-mentioned improvement method was able to eliminate the conventional drawbacks to some extent, it also had drawbacks such as difficulty in adhering the separator and insulating backing, resulting in poor workability, and leakage of electrolyte from between the separator and insulating backing. was there.

The present invention is intended to prevent the above-mentioned drawbacks, and includes an electrolyte retaining layer that covers the cathode agent inserted into the inner wall of an insulating backing interposed at the periphery of a cathode sealing plate filled with a cathode agent containing an electrolyte, and an insulating backing layer that covers the cathode agent. A battery is constructed by heat-sealing an isolation layer covering the electrolyte holding layer to the lower surface of the battery.

An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes a cathode sealing plate made of frozen zinc powder as a cathode active material and filled with a cathode agent 2 containing an electrolyte consisting of an alkaline aqueous solution. butyl methacrylate, methyl methacrylate,
It is coated with a thermal adhesive 3 made of polyisobutylene, coumaron indene resin, polyamide resin, asphalt, etc. dissolved in a container of methyl cyanacrylate, alcohol, toluene, etc. For example, made of polyethylene resin, polyamide resin, polypropylene resin, etc. An insulating backing 4 is interposed.

Reference numeral 5 denotes an electrolyte holding layer made of a nonwoven fabric made of alkali-resistant synthetic resin, which is fitted onto the inner wall 6 of the insulating puffer 4 and covers the cathode material 2.

Reference numeral 7 denotes an isolation layer made of a thin film of polyethylene, polyvinyl alcohol, etc., which is an ion-permeable thermoplastic film made of an ion-permeable thermoplastic film alone or coated with a cellophane film on the anode side. Fusing by heat sealing, ultrasonic vibration, etc.

Next, an anode container 12 filled with an anode mixture 10 mainly composed of an active material such as silver oxide, mercury oxide, manganese dioxide, or nickel hydroxide and a metal ring 11 is placed in the anode container 12 with the cathode sealing plate 1, the cathode agent 2, and the insulator. A backing 4, a cathode body composed of separators 5, 7, etc. are fitted and combined, and the opening 13 of the anode container 12 is bent inward and tightened to form a button-type battery.

As described above, in the present invention, before assembling the cathode side with the anode side, the cathode agent 2 containing an electrolyte is filled into the cathode sealing plate 1, and the lower surface of the insulating backing 4 is coated with a thermal adhesive 3 on the surface. 9
Since the periphery 8 of the isolation layer 7 is heat-fused during battery assembly, the electrolyte will not adhere to the periphery of the cathode sealing plate 1 or leak to the outside during battery assembly. Electrolyte will not leak out of the battery during storage.

Furthermore, since the isolation layer 7 is not displaced or deformed during assembly, there is no internal short-circuit or void formation, thereby preventing deterioration of discharge performance.

Furthermore, since the fusion is performed by heating, the assembly process is simple and the adhesion is good.

In addition, since the electrolyte holding layer 5 is fitted onto the inner wall of the insulating backing 4, the electrolyte is not interposed on the lower surface 9 of the insulating backing 4, and the isolation layer 7 and the insulating backing 4 can be easily bonded to each other, thereby improving workability. and improve leakage resistance.

Furthermore, since leakage and drying of the electrolytic solution can be prevented, the battery discharge characteristics can be improved.

Next, we will discuss the batteries according to the present invention (A, L and the conventional battery CB in which both the electrolyte retaining layer and the isolating layer are fitted and adhered to the inner wall of the insulating backing) and the battery CB made by the method of the present invention in which both the electrolyte retaining layer and the isolating layer are fitted and bonded to the inner wall of the insulating backing. Table 1 shows a comparison of the number of liquid leakages to the outside of the battery when conventional battery C which was not fused was stored at a temperature of 45°C and a humidity of 90%.

In addition, the above-mentioned inventive battery [A], conventional battery [B] and [C] were continuously discharged to 6.5 Ω at 20°C with a final voltage of 1,
Table 2 shows a comparison of the duration characteristics up to 2V and the unevenness.

In addition, the test battery in both Tables 1 and 2 is a WG 10 type silver oxide button battery.

As is clear from the above table, the battery manufactured by the method of the present invention has superior leakage resistance and battery discharge characteristics compared to the conventional method.
Its industrial value is extremely large.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views illustrating steps of an embodiment of the method of the present invention, and FIG. 3 is a cross-sectional view of a battery obtained by the method. 1...Cathode sealing plate, 2...Cathode agent, 4
...Insulating baggage, 5...Electrolyte holding layer, 7...Isolation layer.

Claims (1)

[Scope of Claims] 1. A thermal adhesive is applied to the surface of an insulating backing interposed at the periphery of a cathode sealing plate filled with a cathode agent, and an electrolyte retaining layer covering the cathode agent is fitted onto the inner wall of this backing. At the same time, the cathode body, in which the periphery of an isolation layer made of an ion-permeable thermoplastic film is heat-sealed to the underside of the insulating backing, is fitted into an anode container filled with an anode mixture inside. A method for manufacturing a button-type battery, comprising: bending the opening of the anode container inward and sealing the anode container. 2. The method for manufacturing a button-type battery according to claim 1, wherein the isolation layer is made of a thin film of polyethylene or polyvinyl alcohol alone or a composite film of laminated cellophane films.