JPS60131772A - Electrolyte pouring method of flat battery - Google Patents

Abstract

PURPOSE:To simply and surely pour electrolyte by immersing a flat battery having an electrolyte pouring hole under a reduced pressure in an organic electrolyte and pouring electrolyte by returning to atmospheric pressure into a battery from the electrolyte pouring hole. CONSTITUTION:A lithium metal 3 which serves as a negative active material is press-bonded on the inner surface of a negative current collector 1 also acting as a terminal and having an electrolyte pouring hole 2. The negative part is faced to a positive mix 5 mainly comprising MnO2 which is pressed on the inner surface of a positive current collector 7 also acting as a terminal with a separator 4 interposed between them. These peripheries are sealed with sealant 6 to form a flat battery 8. An organic electrolyte 10 prepared by dissolving LiClO4 in propylene carbonate is filled in a container 9, and a battery 8 is immersed under a reduced pressure in the electrolyte, then the pressure is returned to atmospheric pressure to pour the electrolyte 10 into the battery from the pouring hole 2. Therefore, the electrolyte is surely poured to all portions of the battery.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an improvement in the injection method for an organic electrolyte-based flat battery using lithium as a negative electrode.

Conventional configuration and one point in between: Conventionally, when filling this type of flat battery, the square battery was sealed on three sides to form a bag shape, and the remaining unsealed side was filled twice. The battery was rubbed so that the electrolyte replaced the air in the mesh of the polypropylene non-woven separator and entered the battery quickly.

However, during this liquid pouring and rubbing process, liquid adheres between the parts scheduled to be sealed on the remaining unsealed side, interfering with the seal and weakening the seal strength. □ Also, the electrolyte to be injected is not compatible with the separator, so
There was a drawback that during the rubbing process, the electrolyte overflowed outside the battery, preventing a predetermined amount of the electrolyte from entering the battery. Another disadvantage was that the kneading process took a long time. Additionally, this type of battery is generally pre-discharged.
For a battery of size Xo, g■, the pre-discharge is 1omA.
This was done for 10 minutes, but it had the disadvantage that it was too long.

Purpose of the Invention The present invention solves the above-mentioned conventional drawbacks, and aims to (1) stably inject a certain amount of electrolyte, and (2) inject the electrolyte into the mesh of a polypropylene nonwoven fabric separator that is difficult to absorb the electrolyte. (3) Seal the area around the battery first to prevent the stain-dissolving solution from interfering with the seal around the battery and increase the seal strength; and (4) pre-discharge. The purpose of the present invention is to provide a liquid injection method that can shorten the time required for injection.

Structure of the Invention The present invention involves immersing the injection hole of a flat battery, which has been assembled with all sides sealed in advance, in an electrolytic solution under reduced pressure. The feature is that the liquid is injected by returning the pressure to normal pressure.

According to this configuration, since the massaging step can be omitted, the electrolytic solution does not overflow outside the battery during the massaging step, and a certain amount of the electrolytic solution can be stably poured. In addition, the air in the mesh of the polypropylene nonwoven fabric separator, which is difficult to mix with the electrolyte, is removed, so the liquid can be injected quickly. Also, since the area around the battery is sealed first and then injected, the electrolyte will not leak.
- No more interference between the seal members and lowering the seal strength. Furthermore, since a circuit is formed and discharge occurs at the same time as the liquid is injected, the time required for the preliminary discharge process in the subsequent process can be reduced by approximately 6%.

Description of examples The present invention will be explained in detail below.

FIG. 1 is a sectional view of the assembled flat battery according to the present invention before liquid injection. In the figure, 1 is a Nig negative electrode current collector/terminal whose inner surface is in contact with lithium metal 3, which is the negative electrode active material, and has a liquid injection hole 2 in a part, 04 is a polypropylene nonwoven fabric separator, and '6 is M n O2 7 is a positive electrode current collector and terminal made of stainless steel containing M. 6 is a sealant made of maleic anhydride-modified polyethylene.

FIG. 2 is a top view of the flat battery before injection of liquid, and numeral 1 indicates an electrical body/terminal made by NI that has a liquid injection hole 2.

Figures 3 and 4 are schematic diagrams showing how to pour liquid into the assembled battery. Figure 3 shows the battery before it is immersed in the electrolyte, and Figure 4 shows the battery before it is immersed in the electrolyte. It is in an immersed state. In Figs. 3 and 4, it is an 8Fi battery, and 9 is a container containing an organic electrolyte 10 containing LiCf1o4 dissolved in globylene carbonate. 1 to 7 are the respective configurations shown in Fig. 1. The elements 1 to 10 are all placed in a reduced pressure atmosphere, for example, in a vacuum. Therefore, the air inside the battery 8 in FIG. As shown in Figure 4, after immersing this battery in 1000 of electrolyte solution, dry air etc. is fed into the vacuum chamber to return the pressure to normal pressure, and the injection hole 2 is degassed. The solution 10 is injected into every corner of the battery 8. Therefore, the kneading step as in the conventional method can be omitted. Discharge begins because the liquid junction is short-circuited by the electrolyte. Lithium batteries also have a pre-discharge process (9). The discharge due to this liquid junction is part of the pre-discharge, and up until now it has been carried out in a separate process. The pre-discharge time can be shortened by 6%Ii!.0 Remove this battery from the electrolyte solution, wipe off the electrolyte adhering to the battery/surface, and seal the injection hole using any method.1. Figure 6 shows how the injection hole 2 of the battery is sealed after injection, and 161 is a maleic anhydride-modified port.
This is a sealant made of polyethylene. In the past, it was difficult to wipe off the liquid because the liquid adhered to the seals on the five inner surfaces of the battery, the collector, and the back, but in the present invention, the liquid hole 2 was placed on the outside. In order to prevent rinsing, it is sufficient to simply wipe off the liquid on the outer surface of the battery, and the wiping off is easy and the liquid injection hole 2 can be sufficiently sealed.

Effects of the Invention As is clear from the above embodiments, this book is characterized in that the injection hole of the assembled battery is immersed in an electrolytic solution under reduced pressure, and then the pressure is returned to normal pressure. The liquid injection method of the invention has the following effects.

As described above, the method of the present invention is clearly superior to the conventional method. .

4. Brief explanation of the drawings.

, Figure 1 shows the assembly of the present invention 1, the assembly before liquid injection, the vertical flat,
A cross-section of the battery: the top view, Figure 2, and the - figure, Figure 3.
Figure 3 and Figure 34 are schematic diagrams showing how to inject liquid.
The figure shows the state after the battery is immersed in the electrolytic solution, Figure 4 shows the state after the battery is immersed in the electrolytic solution, and Figure 6 is a top view of the completed flat battery.

1... Negative electrode current collector and terminal, 2... Liquid injection hole, 3... Lithium metal, 4... Separator, 6...・Positive electrode mixture, 6...Sealing agent, 7...Positive electrode current collector/terminal, 8...
-Flat battery, 9...container, 10...electrolyte, 11...sealant.

Name of agent Patent attorney Toshi Nakao 11 or 1 person 4
Diagrams, 5 7

Claims (1)

[Claims] A method for injecting liquid into a flat battery, characterized by injecting liquid by immersing the liquid injection hole of the assembled battery in an electrolytic solution under reduced pressure and then returning the pressure to normal pressure.