JPS612275A - Flat type battery - Google Patents

Abstract

PURPOSE:To increase storage life and discharge performance after storage of a flat type battery utilizing organic electrolyte by specifying a volume ratio of power generating elements to the inner volume of an assembled sealing plate made by combining an insulating gasket and a sealing plate. CONSTITUTION:An assembled sealing plate is fabricated by combining an insulating gasket 2 and a sealing plate 1 with a sealant 3 interposed. When the total volume occupied by power generating elements such as a negative active material 4, a separator 5, a positive active material 6, and electrolyte is limited to 90-100% of the total inner volume, no leakage immediately after assembling of battery is generated. When the ratio of electrolyte to positive active material is limited to 0.80-0.85mul/mg, increase in internal resistance during discharge becomes such large as exceeding 30OMEGA. Therefore, its ratio should be increased to more than 0.85mul/mg.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to improvements in flat batteries, particularly flat batteries using organic electrolytes.

Conventional structure and its problems Conventionally, flat batteries using organic electrolytes have an assembled sealing plate that is made by coupling an insulating pair with a rubber sole and a sealing plate with a sealant between them. The total volume occupied by power generation elements such as the negative electrode active material, separator, positive electrode active material, and electrolyte with respect to the internal volume was 80 to 90%. Furthermore, in order to ensure a high battery capacity, measures have been taken to reduce the amount of electrolyte by putting a large amount of positive and negative electrode active materials into the assembled sealing plate. (The ratio of the absolute amount of electrolyte and positive electrode active material is 0.80 to 85
)J/mg). This is because there is no abnormality in the open circuit voltage, internal resistance, etc. immediately after the battery is assembled, but the internal resistance gradually increases during storage, especially during storage at 6°C. During discharging, the internal resistance increased and the capacity of the battery deteriorated significantly.

Purpose of the Invention The present invention provides a flat battery using an organic electrolyte,
The purpose is to solve the above-mentioned conventional problems regarding storage characteristics and discharge characteristics.

Structure of the Invention In order to achieve the above object, the present invention provides a negative electrode active material, a separator, a positive electrode active material, an electrolytic solution, etc., which are housed in an assembled sealing plate made by coupling an insulating sealing packing and a sealing plate. The total volume of the power generation element is 9% to 100%, and the ratio of the absolute amounts of the electrolyte and the positive electrode active material is at least 0.
It is characterized by having a concentration of 85 pl/mg or more. With such a configuration, it is possible to prevent an increase in internal resistance during storage and a large deterioration in capacity due to an increase in internal resistance during discharge after storage.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The figure shows an insulating sealing packing 2 and a sealing plate 1 according to the present invention.
A negative electrode active material 4. Separator 5. Positive electrode active material6. FIG. 3 is a cross-sectional view showing a state in which power generation elements such as electrolyte are housed.

Table 1 shows the negative electrode active material 4 that occupies an assembled sealing plate made by coupling an insulating sealing packing 2 and a sealing plate 1 with a sealant 3 interposed therebetween. Separator 6, positive electrode active material 6. The results of investigating internal resistance during battery storage and deterioration of discharge capacity after storage in an experiment that combined the total volume of power generation elements such as electrolyte and the ratio of the absolute amounts of electrolyte and positive electrode active material 6 are shown. .

Table 1 However, the discharge capacity is the result of continuous discharge with a constant resistance of Ω at 20° C., and the number of tests was 5 in each case, and the average value is shown.

In addition, negative electrode active material 4. If the total volume of the power generation elements such as the separator 6, positive electrode active material 6, electrolyte, etc. is 80 to 90% or 90 to 100% of the internal volume of the assembled sealing plate, immediately after the battery is assembled as shown in Figure 2. There was no leakage at all, but 100
In the case of 110%, severe leakage occurred immediately after the battery was assembled, so it was excluded from this investigation. The battery size used in this investigation was BR2016, and 7 in FIG. 2 is a case in which the battery also serves as a positive terminal. As is clear from this result, the negative electrode active material 4. Separator 5. Positive electrode active material6. When the total volume of the power generation elements such as electrolyte is 80 to 90%, the internal resistance increases greatly during storage at 60°C, and the capacity deteriorates significantly even during discharge after storage. The reason for this is thought to be that the electrolyte is absorbed into the positive electrode mixture during storage, reducing the total volume within the assembled sealing plate. Separator 6, positive electrode active material 6.
Even if the total volume occupied by power generation elements such as electrolyte is 90 to 100%, the ratio of the absolute amount of electrolyte and positive electrode active material is 0.8
C) -0.86 pH', /ing, the increase in internal resistance during storage is significant L<, and the capacity deterioration during discharge after storage is also significant. The reason for this is clearly a lack of electrolyte. In particular, this type of battery is used for a long period of 5 to 7 years, so the capacity deterioration after storage is 60"C4
Even if stored for 0 days, it is desirable that the amount is 2 cm or less.

Next, Table 2 shows the results of investigating the upper row of internal resistances during discharge of batteries stored at 60 degrees (]441 days.

Table-2 Seal 11 board occupancy rate 80-90 people 90-100% sleep solution
In the discharge layer liquid = active material 0 40 80 0
40 80 degrees % %
% chill gauze'mq Ω
Ω080~0.85 35.4 39,
2 44, 3 33. B 35.6 41.
3ν to 'mq Ω Ω085
~0.90 34.3 37.1 41.6
13.5 14.0 16.3μm2/mg
Ω ΩHowever, this result is 80
The results are based on continuous discharge of a battery with a constant resistance of 20''030 KΩ after storage for 40 days, and the average value of 5 tests is shown.

As is clear from this result, when the total volume occupied by power generation elements such as the negative electrode active material, separator, positive electrode active material, and electrolyte relative to the internal volume of the assembled sealing plate is 80 to 90%, the internal resistance increases during discharge. is severely exceeding 30Ω. Also,
The negative electrode active material, separator, and
Cathode active material.

Even if the total volume occupied by power generation elements such as electrolyte is 90 to 100, the ratio of the absolute amount of electrolyte and positive electrode active material is 0.8
0 to 0.85) 1 w'mq, the internal resistance during discharge increases sharply to 30Ω or more. For batteries used in precision equipment such as electronic watches, the internal resistance during discharge is 3oΩ.
If this happens, the IC of the device may malfunction, or when used in an electronic wristwatch with an alarm or lamp, the alarm may not operate or the lamp may not turn on properly. Therefore, in order to satisfy this condition of 309 or less, the power generation elements such as the negative electrode active material, separator, positive electrode active material, and electrolyte should account for the internal volume of the assembled plate, as shown in Table 2. The total volume is 9Q to 100%, and the absolute amount ratio of the electrolyte and the positive electrode active material is at least 0.85%/
Must be at least mq.

Effects of the Invention As described in detail in the above embodiments, the negative electrode active material, separator, and positive electrode active material with respect to the internal volume of the assembled sealing plate made by coupling the insulating sealing packing and the sealing plate according to the present invention , the total volume occupied by power generation elements such as electrolyte is 9
o ~ 100%, and furthermore, the ratio of the absolute amounts of the electrolyte and the positive electrode active material is at least 0.86 pj! /ing or more, it is possible to significantly improve storage characteristics and discharge characteristics after storage, which are important characteristics of a flat battery using an organic electrolyte.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a power generation element housed in an assembled sealing plate according to the present invention, and FIG. 2 is a view showing the battery after the assembly is completed. 1... Sealing plate, 2... Insulating sealing packing, 4...
...Negative electrode active material, 5--Separator, 6... Positive electrode active material, 7... Case. Name of agent: Patent attorney Takuo Nakao and 1 other person 1st
Figure 1 4. 5 Figure 2 A

Claims (1)

[Claims] A flat battery in which power generation elements such as a negative electrode active material, a separator, a positive electrode active material, and an electrolyte are housed in an assembled sealing plate made by coupling an insulating sealing packing and a sealing plate, and the assembled sealing plate The total volume of power generation elements in the internal volume of is 9
0 to 100%, and the ratio of the absolute amount of the electrolytic solution to the positive electrode active material is at least 0.85 μl/mg or more.