JPH0588514B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention provides a negative electrode using a light metal such as lithium or sodium as an active material, and a positive electrode using a metal oxide, sulfide, or halide as an active material. The present invention relates to a battery equipped with a non-aqueous electrolyte, and particularly relates to a method for manufacturing the battery.

(b) Conventional technology In this type of battery, light metals such as lithium and sodium used as negative electrode active materials are susceptible to surface oxidation due to moisture and oxygen in the atmosphere.
Processing of light metals and battery assembly had to be carried out in an inert gas atmosphere such as argon, which resulted in high equipment costs and poor work efficiency.

Therefore, for example, as disclosed in Japanese Patent Publication No. 51-39343, it has been proposed to process light metals and assemble batteries in a non-aqueous electrolyte, but since the work is done in liquid, the work is complicated. I can't deny it.

(c) Problems to be Solved by the Invention The present invention makes it possible to assemble this type of battery in a dry, moderate atmosphere, thereby reducing equipment costs and increasing work efficiency and productivity. The primary purpose is to measure the Furthermore, the second objective is to reduce the number of parts and reduce battery costs by creating separator members at the battery assembly stage without preparing separators such as synthetic resin non-woven fabrics or films in advance as in the past. purpose.

(d) Means for Solving the Problems The present invention is characterized in that a battery is assembled after applying a polyethylene-polyethylene oxide mixture to the surface of a light metal such as lithium or sodium.

(E) Effect According to the present invention, since the polyethylene-polyethylene oxide mixture is coated on the surface of the light metal, contact with moisture and oxygen can be suppressed by this coated layer. Therefore, it is possible to handle light metals without deteriorating them even in a dry, moderate atmosphere.

Furthermore, in the battery assembly process, when a light metal with a coating layer on its surface as described above is brought into contact with an organic solvent constituting a non-aqueous electrolyte, the polyethylene oxide in the coating layer dissolves into the solvent, while the polyethylene layer dissolves into the solvent. This layer of polyethylene remains and acts as a separator for the battery.

(F) Examples Examples of the present invention will be described below with reference to FIG.

Preparation of negative electrode: After rolling a lithium plate to a thickness of 1.0 mm in argon atmosphere A, a gel-like mixture of polyethylene-polyethylene oxide (weight ratio 1:1) is applied to the surface of the plate to form a coating layer approximately 0.1 mm thick. form 2. Next, this lithium rolled plate was made into a diameter of 20.0 mm.
After punching out a lithium sheet into a diameter of mm, a rolled lithium plate is crimped onto the inner bottom surface of the negative electrode can 3 on which the insulating packing 4 is arranged around the periphery, with the negative electrode current collector 5 interposed therebetween, such that the side without the coating layer is the inner bottom surface side. This is used as negative electrode 1.

Battery assembly: In a dry atmosphere B, a predetermined amount of non-aqueous electrolyte 6 is injected onto the negative electrode. Here, the non-aqueous electrolyte is one in which 1 mol/mol of lithium perchlorate is dissolved in a mixed solvent of equal volume of propylene carbonate and 1.2 dimethoxyethane. After that, the positive electrode can 9 with the positive electrode current collector 8 fixed to the positive electrode 7 and the inner bottom surface is attached, and the opening edge of the positive electrode can is tightened to the insulating packing.
Obtain a button-shaped non-aqueous electrolyte with a size of 25.0 mm and a thickness of 2.8 mm.
Let this battery be X. The positive electrode uses manganese dioxide heat-treated at a temperature of 350 to 430°C as an active material, and this active material is mixed with graphite as a conductive agent and fluororesin as a binder at a weight ratio of 85:10:5. After that, this mixture was made into a shape with a diameter of 20.0 mm and a thickness of 1.2 mm.
It was obtained by pressure molding to a size of 1.5 mm and then vacuum heat treatment at 250 to 350°C.

Next, a comparative battery was prepared in order to examine the superiority of the battery obtained by the method of the present invention.

Comparative Example 1 Using a lithium negative electrode without applying a polyethylene-polyethylene oxide mixture, using a polypropylene nonwoven fabric as a separator,
and a first comparative battery Y ₁ in the same manner as the example of the present invention except that the battery assembly was performed in an argon atmosphere.
It was created.

Comparative Example 2 A second comparative battery _Y2 was prepared in the same manner as in the example of the present invention, except that a lithium negative electrode was not coated with a polyethylene-polyethylene oxide mixture, and a polypropylene nonwoven fabric was used as a separator.

Figure 2 is a comparison diagram of the discharge characteristics of these batteries.
Shows 560Ω constant load discharge characteristics at 25℃.

(g) Effects of the invention As is clear from FIG. ₂ , _the battery It shows the characteristics.

The reason for this is considered to be that in the case of the first comparative battery _Y1 , the battery was assembled in an argon atmosphere, so there was no deterioration of the lithium negative electrode. However, as mentioned at the beginning, this battery has the problems of high equipment costs and low work efficiency.

In the case of the second comparative battery, deterioration of the lithium negative electrode during battery assembly is considered to be the cause.

On the other hand, in the case of battery Therefore, it is thought to exhibit excellent battery characteristics, and in particular, it is possible to assemble the battery in a dry atmosphere, which reduces equipment costs and increases work efficiency, leading to improved productivity.

In addition, when the coating layer comes into contact with the non-aqueous electrolyte, the polyethylene oxide is eluted and the remaining polyethylene layer acts as a separator, eliminating the need for a separate separator member, reducing the number of parts and reducing battery costs. It is possible to reduce the amount of carbon dioxide, and its industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the manufacturing process of a battery according to the present invention, and FIG. 2 is a diagram showing the discharge characteristics of the battery. 1... Lithium negative electrode, 2... Coating layer, 3... Negative electrode can, 4... Insulating packing, 6... Non-aqueous electrolyte, 7... Positive electrode, 9... Positive electrode can, A... Argon atmosphere area, B...Dry atmospheric region, X...Battery according to the present invention, _Y1 , _Y2 ...Comparative battery.

Claims (1)

[Claims] 1. A battery comprising a negative electrode using a light metal such as lithium or sodium as an active material, a positive electrode, and a non-aqueous electrolyte, characterized in that the battery is assembled after applying a polyethylene-polyethylene oxide mixture to the surface of the light metal. A method for manufacturing a non-aqueous electrolyte battery.