JPS6023957A - Manufacture of nonaqueous electrolytic battery - Google Patents

Abstract

PURPOSE:To improve the close circuit voltage characteristics and pulse characteristics as the initial discharge stage, improve productivity due to the simplification of manufacturing process, increase capacity, and stabilize battery characteristics by comprising a battery after the carbon fluoride as positive electrode active material pressurized and molded in a pellet shape is previously constant- current-discharged in an electrolyte. CONSTITUTION:When a nonaqueous electrolyic battery that uses mettalic lithium 4 as the negative electrode active material and carbon fluoride as the positive electrode active material is manufactured, constant current discharge is executed previously for the carbon fluoride as the positive electrode active material molded in a pellet shape (a) and the battery is comprised using it as a positive electrode 6. For example, after the carbon fluoride as the positive electrode active material is pressurized and molded in a pellet shape (a), it is dipped in a mixed solution composed of gamma-butyrolactone and 1,2 dimethoxy ethane as the electrolyte. While they are being slowly agitated by an agitation blade c using a lithium rod as a paired electrode b, constant current discharge is executed by connecting a power supply d. In this case, the constant current condition is set to 3-5% of total capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a non-aqueous electrolyte battery that uses metallic lithium as a negative electrode active material and fluorocarbon as a positive electrode active material.

Conventional/example configurations and their problems This type of battery is lighter than silver oxide batteries and has a flat discharge rate of about 2.8V, so it has been used in various fields in recent years. It is expected.

Conventionally, this type of battery generally has a closed-circuit voltage characteristic at the beginning of discharge due to the characteristics of fluorinated carbon, which is the positive electrode active material, and shows the lowest voltage several hours immediately after discharge.
Furthermore, it shows a tendency to gradually increase as the depth of discharge progresses.

When the closed circuit voltage reaches the lowest value several hours after starting this discharge, the voltage in the strong load pulse characteristic also shows the lowest value.

Therefore, by reducing this voltage, in applications that require heavy load characteristics such as Lang Malam, etc., such as time opening, etc.
Improvements were inevitable.

Conventionally, as a method for solving this type of problem, a method has been proposed in which a battery is constructed and then subjected to constant current discharge. However, the conventional method has the following drawbacks.

(1) If constant current discharge has to be carried out to 3 to 5% of the total capacity, there will be a loss of 3 to 6% of the total capacity (loss).

? ) Facility 2 for further constant current discharge after configuring the battery.
It takes time, effort, etc., and increases the cost.

-(3) If the current value is increased in order to carry out the test in a short period of time, the open circuit voltage will reverse, lithium will be deposited, and the static characteristics of the battery will vary.

(4) Since individual characteristics such as voltage and current vary when configuring battery characteristics, when constant current discharge is performed, the variations in characteristics such as capacity, voltage, and current further increase.

(6) After implementing constant current, aging was required to restore open circuit voltage, detect defects, etc.

In the process of researching such batteries, the present inventors discovered 7
By carrying out constant current discharge at the time of pressure molding the carbon noride, it is possible to prevent voltage drop, especially in the initial stage, compared to when carrying out constant current discharge after constructing the battery.
It was found that the largest capacity can be obtained among the same volumes, and this invention was completed.

Purpose of the Invention The present invention solves the various problems mentioned above, improves the closed circuit voltage characteristics and pulse characteristics at the initial stage of discharge, and improves mass productivity by simplifying the manufacturing process, increases capacity, and stabilizes battery characteristics. The present invention provides an inexpensive and highly reliable non-aqueous electrolyte battery.

Structure of the Invention In the present invention, carbon heptanoide, which is a positive electrode active material, is press-molded into pellets before battery construction, and the pellets are discharged at a constant current in an electrolytic solution, and then the battery is constructed. .

According to this manufacturing method, the discharge of the positive electrode can be easily performed in a short time during the manufacturing process. If you increase the positive electrode active material by 3 to 5 in advance, the negative electrode active material will not be consumed, so you can increase the capacity by 3 to 5 times. Furthermore, even if constant current discharge is performed for a short period of time, since there is only an electrolyte and a positive electrode active material, a battery of stable quality can be obtained without deterioration of the separator, and there is little effect on the voltage, current capacity, etc. of the battery. , there are advantages such as less variation.

DESCRIPTION OF EXAMPLES The present invention will be described in detail below. As shown in FIG. , 2 dimethoxyethane, and using a lithium rod as a pair of electrodes, while stirring slowly with a stirring blade C, a power source d is connected to perform constant current discharge.

At this time, the constant current condition is 3% to S of the total capacity.

This is because if it is 3 or less, there is no effect of suppressing the drop in the closed circuit voltage, and even if 6 or more steps are carried out, no further increase in voltage will be observed, and only a decrease in capacity will proceed.

Figure 2 shows a lithium-fluorocarbon flat organic electrolyte battery using the positive electrode of the present invention. 22.9 + nm, height 2.7 CH nm battery case, 2 (l-j: 1) and a sealing plate processed from the same material as 21.2 mm in outer diameter and 1.60 in H%; 3 is a negative electrode current collector made of a nickel foam with a diameter of 18 mm, a thickness of 0.27 mm, and a porosity of 86%, spot welded to the inner surface of the sealing plate, and 4 is a negative electrode current collector made of a nickel foam with a diameter of 17 mm and a thickness of 0.31 m.
A negative electrode active material consisting of a lithium sheet of m is crimped to the current collector 3. 6 has a diameter of 16mm.

A positive electrode current collector made of expanded titanium metal with a thickness of 0.15 rMl is spot welded to the inner surface of the case 1. 6 is a positive electrode mixture, after press-molding fluorocarbon, which is an active substance IF, into a pellet shape together with a conductive material,
After performing constant current discharge, which is a feature of the present invention, it was molded into a case. 7 is a separator made of polypropylene nonwoven fabric. The electrolyte contains γ-butyrolactone and 1
, 2-dimethoxyethane and lithium borofluoride dissolved at a ratio of 1 mol/l was used.

After impregnating the negative electrode current collector fixed to the sealing plate and the positive electrode fixed to the case with the electrolytic solution, 7); Wrap the peripheral edge of the tray under the polypropylene insulating backing 8 and swage it together with the sealing plate. and constructed a battery. This battery has a total height of 2.5 mm and a capacity of 160 mAh.

3 and 4 show a load of 15 KQ and a temperature of 2 to compare the conventional battery A and the battery port of this embodiment.
Initial discharge curve at 0℃ and load 16KQ.

The pulse characteristics at each temperature when the closed circuit voltage of discharge at a temperature of 20'C is the lowest are shown.

Effects of the Invention As is clear from the above examples, a battery constructed using a pellet-shaped positive electrode active material that has been subjected to constant current discharge in advance has poor closed-circuit voltage and pulse characteristics at the initial stage of discharge. This is improved compared to the conventional method, the manufacturing process can be simplified, mass productivity can be improved, and a low-cost battery can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing constant current discharge of a pressurized positive electrode mixture in an embodiment of the present invention, FIG. 2 is a longitudinal cross-sectional view of a flat valve water electrolyte battery in an embodiment of the present invention, and FIG. A comparison diagram of the initial discharge voltage, FIG. 4, is a diagram showing the pulse characteristics at each temperature at the initial stage of discharge. a... Positive electrode mixture formed into pellets, 3...
... Negative electrode current collector, 4... Negative metal lithium, 5... Positive electrode current collector, 6... Positive electrode mixture,
.

Claims (1)

[Claims] A method of manufacturing a non-aqueous electrolyte battery using metallic lithium as a negative electrode active material and fluorocarbon as a positive electrode active material, in which fluorocarbon, which is the positive electrode active material, is formed into pellets and then subjected to constant current discharge in advance. A method for manufacturing a non-aqueous electrolyte battery, which comprises using it in a gyokurou to form a battery.