JP2001185219A - Electrolyte inclusion separator for lithium ion secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolyte inclusion separator for a lithium ion secondary battery, in which the manufacturing process of the lithium ion secondary battery can be simplified and in which the electrolyte is made to be spread throughout the battery. SOLUTION: A cell 18, in which an electrolyte is enclosed in the separator 16 used in the lithium ion secondary battery, is made to form around 50% in volumetric ratio. After the lithium ion secondary battery has been configured using such a separator 16, the inside of the battery is turned into negative pressure, the electrolyte in the cell 18 is made to discharge, and then the necessary electrolyte is made to be spread throughout the lithium ion secondary battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separator used for a lithium ion secondary battery, and more particularly to an electrolyte sealed separator for a lithium ion secondary battery in which an electrolyte is sealed.

[0002]

2. Description of the Related Art A lithium ion secondary battery has a structure in which a positive electrode and a negative electrode are laminated via a separator in order to retain an electrolytic solution and prevent a short circuit between the positive electrode and the negative electrode. In such a lithium ion secondary battery, the electrolyte is injected into the battery after the laminate of the positive electrode, the negative electrode, and the separator is wound or accommodated in the battery case.

[0003] However, according to such a method, it is not possible to confirm whether or not the electrolyte has sufficiently spread in the battery, and there is a problem that the manufacturing process of the lithium ion secondary battery is complicated.

[0004] Therefore, if the separator is impregnated with an electrolytic solution in advance and a lithium ion secondary battery is prepared using such a separator, the problem that the electrolytic solution does not sufficiently spread to the separator can be solved. Japanese Patent Application Laid-Open No. H10-64503 discloses an example of a method for producing a lithium ion secondary battery using such a separator impregnated with an electrolytic solution in advance.

[0005]

However, in the above conventional example, a method is used in which a microporous polyvinylidene fluoride membrane is used as a separator, and after swelling with a polar organic solvent, the impregnating solvent is replaced with an electrolytic solution. The problem that the manufacturing process is complicated is not solved. In addition, there is a problem that even if the electrolyte is sufficiently held in the separator, the electrolyte may not be sufficiently supplied to the electrodes.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to simplify a manufacturing process of a lithium ion secondary battery, and to provide a lithium ion secondary battery capable of reliably dispersing an electrolyte in the battery. An object of the present invention is to provide an electrolyte-filled separator for an ion secondary battery.

[0007]

In order to achieve the above object, the present invention provides an electrolyte for a lithium ion secondary battery used for a lithium ion secondary battery in which a positive electrode and a negative electrode are laminated via a separator. An enclosed separator, comprising a small chamber for filling an electrolytic solution, wherein the electrolytic cell sealed in the small room is released by breaking the small room, thereby completing conduction in the battery.

In the above-mentioned electrolyte-filled separator for a lithium ion secondary battery, the small chamber is formed of microcapsules, and the means for breaking the small chamber is a negative pressure.

[0009]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

FIG. 1 shows a lithium ion 2 according to the present invention.
A cross-sectional view of a lithium ion secondary battery using an electrolyte-filled separator for a secondary battery is shown. In FIG. 1, a positive electrode 12 and a negative electrode 14 formed on a current collector foil 10 are stacked via a separator 16. By winding such a laminate or laminating it in a battery case in this state, a lithium ion secondary battery is formed.

FIG. 2 is an enlarged sectional view of the separator 16 used in the lithium ion secondary battery shown in FIG. In FIG. 2, the separator 16 has a large number of small chambers 18 in which an electrolyte is sealed. This small room 1
The electrolyte solution sealed in the chamber 8 is released from the chamber 18 when the chamber 18 is broken, and the separator 16 and the cathode 1
2. It can be spread to the negative electrode 14 and the like to complete the conduction in the battery. As described above, by configuring the lithium ion secondary battery using the separator 16 in which the electrolyte is sealed in the small chamber 18 in advance, the process of injecting the electrolyte into the battery and distributing the electrolyte can be simplified. Can be. In addition, it is possible to ensure that the electrolytic solution is distributed throughout the battery.

As a means for breaking the small chamber 18, for example, a negative pressure in the battery case can be considered. That is, the laminate shown in FIG. 1 is constituted by using the separator 16 and wound or housed in a battery case, and then the inside of the battery is evacuated to a negative pressure to break the small chamber 18. The internal electrolytic solution is released, and the electrolytic solution can be easily spread throughout the battery.

The small chamber 18 shown in FIG. 2 is not particularly limited as long as it is configured to release the retained electrolyte by breaking when the inside of the battery is evacuated to a negative pressure. Absent. For example, it is also preferable to form the small chamber 18 with microcapsules in which an electrolyte is sealed. In such a small chamber 18, when a negative pressure is applied, it is necessary to supply a sufficient electrolytic solution to the separator 16, the positive electrode 12, and the negative electrode 14. Therefore, the small chamber 18 in the separator 16 has a volume ratio of It is preferable to set it to about 50%.

[0014]

As described above, according to the present invention,
After configuring the lithium ion secondary battery, it is possible to easily spread the electrolytic solution into the battery by setting the inside of the battery to a negative pressure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a lithium ion secondary battery using an electrolyte-filled separator for a lithium ion secondary battery according to the present invention.

FIG. 2 is a cross-sectional view of a configuration of an electrolyte-filled separator for a lithium ion secondary battery according to the present invention.

[Explanation of symbols]

10 collector foil, 12 positive electrode, 14 negative electrode, 16 separator, 18 small chamber.

Claims (2)

[Claims] An electrolyte-filled separator for a lithium-ion secondary battery used for a lithium-ion secondary battery in which a positive electrode and a negative electrode are stacked with a separator interposed therebetween, comprising: a small chamber for sealing an electrolyte; An electrolyte-filled separator for a lithium ion secondary battery, characterized in that by breaking the small chamber, the electrolyte sealed in the small chamber is released to complete conduction in the battery. 2. The electrolyte-filled separator for a lithium ion secondary battery according to claim 1, wherein the small chamber is formed of a microcapsule, and the means for breaking the microcapsule is a negative pressure. Electrolyte-filled separator for lithium ion secondary batteries.