JPS6348778A - Manufacture of cell - Google Patents

Abstract

PURPOSE:A high-performance battery with a practical size is easily and surely manufactured by reducing the pressure in a battery case, and injecting and charging the decompressed battery case with an electrolyte. CONSTITUTION:First of all, a three way cock 4 is operated to open a passage 5 and close a passage 9 and a vacuum pump 6 is operated to reduce the pressure in a battery case 1 until it reaches the prescribed reduced pressure. When the pressure reaches the prescribed pressure the three way cock 4 is changed over to close the passage 5 and open the passage 9. Thus, a electrolyte 7 charged in a container 8 is made not to flow to the vacuum pump 6 side, and it is immediately injected into the battery case 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application The present invention uses a conductive polymer material as a Wl electrode active material for at least one of a positive electrode and a negative electrode.

The present invention relates to a method of manufacturing a battery in which a negative electrode and an electrolyte are housed in a battery case, and more specifically, to a method of manufacturing a battery that can easily and reliably manufacture a practical-sized battery with excellent battery performance.

Warabi Exposure (9-Techniques and U tries to do 3. J Title 1) In recent years, batteries have been developed in which conductive polymer materials are used as electrode active materials for at least one of the positive and negative electrodes in order to make the batteries smaller and lighter. Among them, polyaniline is attracting attention as an electrode active material that can form batteries with a large discharge capacity and a secondary battery with an excellent repeated charging and discharging life. Attempts have been made to use positive electrode active materials to form batteries such as lithium secondary batteries with high energy density.

On the other hand, at the same time as these attempts, what about batteries? I! The development of conductive polymer materials suitable as electronic materials such as polar active materials has been actively carried out, and as a result, Akiko Kinie et al. We have proposed polyaniline suitable as an electronic material such as.

However, when a conductive polymer material such as polyaniline is used as an active material for at least one of a positive electrode and a negative electrode, and a secondary battery is constructed by housing the positive electrode, negative electrode, and electrolyte in a battery case, Although laboratory-grade batteries such as beaker cells have high battery voltage and discharge capacity, and have excellent charge/discharge cycle life, practical-sized secondary batteries such as cylindrical batteries and coin-shaped batteries with similar components cannot be used. However, when configuring this type of battery, a problem arose in that the battery voltage, discharge capacity, and charge/discharge cycle life were significantly lower than those of laboratory-grade secondary batteries.

The present invention has been made in view of the above circumstances, and it is possible to obtain a cylindrical or coin-shaped battery that has a battery voltage, discharge capacity, and charge/discharge cycle life comparable to that of secondary batteries such as beaker cells. The object of the present invention is to provide a method for manufacturing a battery using a conductive polymer material as an electrode active material, which can easily and reliably produce a high-performance, practical-sized battery.

Methods and actions for solving point U In order to achieve the above object, the present inventors first developed a laboratory-level beaker cell type secondary battery, and a cylindrical battery constructed from similar components. In order to investigate the causes of differences in battery performance, such as battery voltage, discharge capacity, and repeated charging/discharging life, between the two batteries and a practical-sized secondary battery such as a coin-type battery, we investigated the two batteries in detail. I guessed it. As a result, in the laboratory-grade beaker cell type secondary battery mentioned above, a decrease in the amount of electrolyte was observed because the amount of electrolyte was sufficiently rich relative to the conductive polymer material used for the electrode active material. On the other hand, in a practical-sized secondary battery, as is clear from the comparative example described later, even if the electrolyte is poured into the battery case with the positive and negative electrodes, it is sufficient. B: When a large amount of electrolyte is injected, the contact between the electrode and the electrolyte may become insufficient, such as a shortage of liquid over time and the formation of a non-contact area between the electrode and the electrolyte. It was enshrined. In addition, this liquid shortage that occurs with the passage of time is almost impossible if the conductive material obtained by solidifying a metal material or powdered conductive substance with a paste binder is used as an ffi extremely active extremely poor substance. However, it is particularly noticeable when a conductive polymer material that can be considered to be substantially porous, such as polyaniline with a fibrous structure, is used as the electrode active material. 2 to 5 mol/
When using an electrolyte with a significantly higher viscosity and surface tension than a normal electrolyte aqueous solution, such as a non-aqueous electrolyte containing a high a degree electrolyte, the above-mentioned increase in liquid shortage over time occurs. was observed even more clearly.

Therefore, in the manufacturing process of practical-sized batteries, a conductive polymer material that can be considered as a substantially porous material such as polyaniline with a fibrous structure is used as the electrode active material, and a highly viscous non-woven material containing a high concentration of electrolyte is used as the electrode active material. Even when an aqueous electrolyte is used, wetting and permeation of the electrolyte into the electrode active material proceed smoothly from the beginning of battery manufacture, making it possible to inject and fill a sufficient amount of the electrolyte, and over time, there is no shortage of electrolyte inside the battery. As a result of intensive research on ways to prevent the increase in occurrence, we decided to reduce the pressure inside the battery case that houses the positive and negative electrodes.

Next, when the electrolyte is injected into the reduced pressure battery case to fill it, a large amount of electrolyte is quickly injected before filling, compared to the conventional method in which electrolyte is injected and filled without applying reduced pressure. In addition, the resulting battery has several levels of battery performance, such as a secondary battery with superior battery voltage, discharge capacity, and charge/discharge cycle life compared to batteries manufactured using conventional methods. It was discovered that an improved battery could be obtained, and the present invention was completed.

Therefore, the present invention provides a method for manufacturing a battery in which a conductive polymer material is used as an electrode active material for at least one of a positive electrode and a negative electrode, and the positive electrode, the negative electrode, and an electrolyte are housed in a battery case. Three methods of manufacturing a battery are provided, in which the pressure inside the battery case is reduced, and then an electrolyte is injected into the reduced pressure battery case to fill it.

The present invention will be explained in more detail below.

The present invention uses a conductive polymer material as one active material of at least one of a positive electrode and a negative electrode, and also uses a conductive polymer material as an active material of at least one of a positive electrode and a negative electrode.

When manufacturing a battery by housing the negative electrode and electrolyte in a battery case, in the electrolyte injection filling process.

Before injecting electrolyte into the battery case, the pressure inside the battery case is reduced in advance, and then the electrolyte is injected into the battery case under the reduced pressure, thereby ensuring that a sufficient amount of electrolyte is Practical-sized batteries such as cylindrical batteries and coin-shaped batteries, which are filled, have a large discharge capacity, and have an excellent charge/discharge cycle life can be obtained.

Here, the pressure reduction inside the battery case before filling the electrolyte into the battery case depends on the size of the battery case and the pressure inside the battery case depending on the type of battery being manufactured, such as a cylindrical battery or a coin type battery. The pressure reduction method, degree of pressure reduction, etc. are selected as appropriate depending on the contents, the type of conductive polymer material used for the electrode active material, the components and composition of the electrolyte, etc., and the specifics of the pressure reduction method are not particularly limited. For example, a battery case containing an electrode using a conductive polymer material as the electrode active material is airtightly covered with a lid with a hollow tube attached to it, and the battery is connected to the hollow tube directly or through a pressure regulator. There is a method of connecting a vacuum pump and operating the vacuum pump to reduce the pressure inside the battery case to a predetermined degree of decompression, or a method of storing multiple battery cases in a large container and using the container as a lid with a hollow tube attached. Connect the hollow tube to the same vacuum pump as above to reduce the pressure inside the container.

Examples include a method of simultaneously reducing the pressure in a plurality of battery cases housed in this container to a predetermined degree of pressure reduction. Also,
The degree of decompression is usually less than 20 Hg, especially IQnn.
It is preferable to set it to Hg or less.

Note that in the method of the present invention, after the pressure inside the battery case is reduced, the electrolyte is further injected into the reduced pressure battery case to fill it.
After the electrolyte is filled, the electrolyte is reliably and quickly injected until the predetermined filling amount is reached, without causing or increasing liquid shortage over time, so no special injection operation is required. Appropriate liquid injection operations can be adopted according to conventional methods, such as pressurized liquid injection when the viscosity of the liquid is high.

Here, in the present invention, a conductive polymer material is used as an electrode active material for at least one of the positive electrode and the negative electrode, but the conductive polymer material is not particularly limited, and for example, polyacetylene obtained by polymerization is used. , polyaniline, polypyrrole, etc., or graphite obtained by firing organic materials.

Examples include boriacene and amorphous carbon.

However, it is possible to effectively use conductive polymer materials, such as polyaniline, which has a fibrous structure in which fibrils are densely intertwined, and which are difficult to penetrate with electrolyte in conventional methods. Even in such a case, according to the present invention, penetration of the electrolyte can be improved and a high-performance battery can be obtained. In this case, when a conductive polymer material is used as the active material of one electrode, a known electrode active material is used as the active material of the other electrode. There are no restrictions on the types of electrolytes or solvents used in battery electrolytes.
Although various selections may be used, in the present invention, 2 to 5 mol/
High viscosity containing electrolyte of Q grade.

Non-aqueous electrolytes with high surface tension can also be used effectively, and even with such non-aqueous electrolytes, a sufficient amount of electrolyte can be reliably and quickly filled into the battery case, thereby saving energy. Batteries with high density can be easily manufactured.

Note that other battery constituent materials are also appropriately selected depending on the type of battery, etc.

In addition, the method of the present invention is not particularly limited to the battery assembly process that is performed before this process and the can sealing process that is performed after this process, except for the above-mentioned electrolyte injection filling process. 1. The method used in normal battery manufacturing can be adopted.

Natsuki Miiri As explained above, according to the present invention, a positive electrode.

When manufacturing a battery in which a conductive polymer material is used as the electrode active material for at least one of the negative electrodes and the positive and negative electrodes and electrolyte are housed in a battery case, it is easy and reliable to place a sufficient amount of electrolyte in the battery case. The electrolyte can be injected and filled into the conductive polymer material, and the electrolyte can be sufficiently soaked into the conductive polymer material. types of polymeric materials and components of electrolyte.

It is resolved regardless of the composition etc. Therefore, it is polyacetylene.

Organic conductive polymer materials such as polyaniline and polypyrrole, polythiazyl, and inorganic conductive polymer materials such as graphite, boriacene, and amorphous carbon obtained by firing organic materials are used as electrode active materials, and they contain a high concentration of electrolyte. It is possible to obtain practical-sized batteries such as cylindrical batteries and coin-type batteries with excellent battery performance by using electrolytes such as non-aqueous electrolyte solutions.
i'M, since there is no need to replenish the electrolyte corresponding to the shortage after the occurrence of a shortage of the solution, the above-mentioned high-performance, practical-sized battery can be manufactured efficiently.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples.

〔Example〕

A separator made of polypropylene nonwoven fabric was interposed between a positive electrode using 3.6 g of polyaniline as a positive electrode active material and a negative electrode using 1.6 g of lithium as a negative electrode active material, and these were wound into a spiral shape to form an inner diameter of 21.5 mmφ.
It was housed in a battery case with a height of 40 m.

The inside of this battery case is l
When the pressure was reduced to mHg and then an electrolytic solution (3 mol L x B F 4 /propylene carbonate) was injected into the reduced pressure battery case, 8.0 cc could be filled in about 6 seconds, and after filling. The sealing work was also carried out reliably.

Here, in the reduced pressure liquid injection device shown in the drawings, the upper end opening of the battery case 1 is closed, a silicone stopper 2 is attached, a hollow tube 3 is attached to the stopper 2 through approximately the center thereof, and a A three-way cock 4 is attached to a pipe 3, a vacuum pump 6 is attached to one side of the three-way cock 4 via a channel 5, and a container 8 containing an electrolyte 7 is attached to the other via a channel 9. To operate the reduced-pressure juice using this device, first open the flow path 5 by operating the three-way cock 4, and then open the flow path 9.
With the battery case 1 closed, the vacuum pump 6 is operated to reduce the pressure inside the battery case 1 until a predetermined degree of pressure reduction is reached. Next, when a predetermined reduced pressure is reached, the three-way cock 4 is switched to close the flow path 5 and open the flow path 9. As a result, the electrolytic solution 7 contained in the container 8 does not flow toward the vacuum pump 6, and is quickly poured into the depressurized battery case 1. When the amount of electrolyte in the battery case 1 reaches the filling amount, the three-way cock 4 is switched again to close the flow path 9. In addition, in the figure, 10 is a positive electrode, 11 is a negative electrode, and 12 is a separator.

The battery manufactured by the above method was charged to 3.8V with a charging current of 40mA, and then 2.5V with a discharge current of 40mA.
When I discharged to v and measured the discharge capacity, the discharge capacity was 4.
00 mA.

Next, 10 cycles of charging and discharging were performed, with the above charging and discharging being one cycle, and the discharge capacity at this point was measured. No decrease in the discharge capacity was observed even after 10 cycles.

[Comparative example]

An attempt was made to manufacture a battery similar to that of the example according to a conventional method without performing vacuum injection.

As a result, the inside of the battery case containing the same contents as in the example became full after approximately 2.5 liters of liquid was injected. However, after that, as bubbles were generated, electrolyte shortage occurred and increased, so injection was continued to replenish the shortage, but the amount of electrolyte injected after 1 hour was 6.
．． 9 cc, bubbles were still observed to be generated from the electrolyte in the battery case, and sealing the battery case could impede battery performance.

However, when a battery was manufactured by sealing at this point and the resulting battery was charged with a charging current of 40 mA, the charging voltage reached 3.75 VT saturation. Then 3.75V
When the battery was discharged at a discharge current of 40 mA from 2.5 to 2.5, the discharge capacity was 180 mA.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing an embodiment of a reduced pressure liquid injection device according to the present invention. DESCRIPTION OF SYMBOLS 1... Battery case, 2... Lid body, 4... Three-way cock, 6... Vacuum pump, 7... Electrolyte, 8... Container.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a battery in which a conductive polymer material is used as an electrode active material for at least one of a positive electrode and a negative electrode, and the positive electrode, negative electrode, and electrolyte are housed in a battery case, A method of manufacturing a battery, comprising reducing the pressure inside the battery case, and then injecting and filling the reduced pressure battery case with an electrolyte. 2. The manufacturing method according to claim 1, wherein the conductive polymer material is polyaniline.