JPS6352749B2 - - Google Patents

Description

[Detailed description of the invention] Technical field The present invention relates to non-aqueous electrolyte batteries.

This type of battery uses alkali light metals such as lithium and sodium as the negative electrode active material, metal oxides, chlorides, or halogen carbon compounds as the positive electrode active material, and propylene carbonate, 1,2-dimethoxyethane, It uses a solute such as lithium perchlorate or lithium borofluoride dissolved in a solvent such as γ-butyllactone, and has many advantages such as high voltage, high energy density, and little self-discharge. It is equipped with the following.

Background Art As a specific example of this type of battery, lithium is used as a negative electrode active material, manganese dioxide is used as a positive electrode active material, and a lithium perchlorate solute dissolved in a mixed solvent of propylene carbonate and 1,2 dimethoxyethane is used as an electrolyte. Non-aqueous electrolyte batteries have been put into practical use.

Lithium perchlorate, which is used as a solute in this type of battery, has extremely strong oxidizing power, and therefore, when this type of battery is used at high temperatures (for example, over 200°C), it may cause a combustion reaction with the solvent, etc. However, there is a concern that it may cause heat generation and destruction of the battery.

DISCLOSURE OF THE INVENTION The present invention was developed as a result of intensive studies to solve the above-mentioned problems, and its gist is that lithium perchlorate and (LiCF ₃ SO ₃ (trifluoromethane sulfur) The point is that it uses two components: lithium fluoride).
(LiCF ₃ SO ₃ (lithium trifluoromethanesulfonate) reduces the oxidizing power of lithium perchlorate to provide a non-aqueous electrolyte battery that is highly safe even at high temperatures.

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the present invention will be described below.

Example 1 Commercially available manganese dioxide heat-treated in air at 250 to 450°C was used as a positive electrode active material, and acetylene black and graphite as conductive agents and fluororesin powder as a binder were appropriately added to this active material powder. Mix thoroughly at a suitable weight ratio to form a positive electrode mixture.

Next, this positive electrode mixture was pressure-molded at a pressure of approximately 1 ton/cm ² to obtain positive electrode pellets with a diameter of 15 mm and a thickness of approximately 1.1 mm, and then the positive electrode pellets were fired at a temperature of 250 to 300°C. Use as positive electrode.

The negative electrode is made by rolling a lithium plate to a thickness of approximately 0.6 mm.
This lithium rolled plate is punched out to a diameter of 15 mm.

As an electrolyte, a solute of lithium perchlorate and (LiCF ₃ SO ₃ (lithium trifluoromethanesulfonate)) was added to an equal volume mixed solvent of propylene carbonate and 1,2 dimethoxyethane, respectively.
Use 0.8 mol/dissolved and 0.2 mol/dissolved solution.

FIG. 1 shows a longitudinal cross-sectional view of the battery of the present invention, in which 1 and 2 are positive and negative electrode cans, which are electrically insulated by an insulating packing 3. 4 is a positive electrode that is in pressure contact with the inner bottom surface of the positive electrode can 1 via a positive electrode current collector 5;
Further, 6 is a negative electrode which is pressed into contact with the inner bottom surface of the negative electrode can 2 via a negative electrode current collector 7. A separator 8 is inserted between the positive and negative electrodes, and is impregnated with a predetermined amount of the electrolyte that is the gist of the present invention. Let this battery be (A ₁ ).

Example 2 As an electrolyte, 0.5 moles each of lithium perchlorate and LiCF ₃ SO ₃ (lithium trifluoromethanesulfonate) solutes were dissolved in an equal volume mixed solvent of ethylene carbonate and 1,2 dimethoxyethane. A battery (A ₂ ) was prepared in the same manner as in Example 1 except for the use of the following.

Example 3 The electrolyte used was an electrolyte in which 0.5 mol each of lithium perchlorate and LiCF ₃ SO ₃ (lithium trifluoromethanesulfonate) solutes were dissolved in an equal volume mixed solvent of propylene carbonate and tetrahydrofuran. The rest is Example 1
A similar battery (A ₃ ) was made.

Next, for comparison, an equal volume mixed solvent of propylene carbonate and 1,2 dimexyethane was used as an electrolyte, and 0.8% of lithium perchlorate was added as a solute.
A comparative battery similar to the battery of the present invention was prepared using the mol/dissolved product.

Figure 2 shows the batteries A ₁ , A ₂ , A ₃ of the present invention and comparative battery B.
The graph shows the temperature change characteristics of each battery when the battery is placed in the sand and the sand temperature (broken line) is increased.

From FIG. 2, it can be seen that in comparison battery B, the temperature of the battery itself suddenly rises abnormally from around 200°C, whereas in the batteries A ₁ , A ₂ , and A ₃ of the present invention, the ambient temperature rises to 300°C. No abnormal rise in the temperature of the battery itself was observed even after the test.

The reason for this is that the comparison battery uses lithium perchlorate, which has a strong oxidizing power, alone as the solute that makes up the electrolyte, so at high temperatures, this lithium perchlorate and the solvent cause a combustion reaction, causing the temperature of the battery itself to rise. It is thought that there will be an abnormal increase in

On the other hand, if two components, lithium perchlorate and (LiCF ₃ SO ₃ lithium trifluoromethanesulfonate), are used as solutes constituting the electrolyte as in the battery of the present invention, (LiCF ₃ SO ₃ (lithium trifluoromethanesulfonate) It is believed that the lithium perchlorate acts to suppress the oxidizing power of the lithium perchlorate and can solve the problem in the comparative battery.

Effects of the Invention According to the battery of the present invention, it is possible to provide a non-aqueous electrolyte battery that is extremely safe even under high temperatures.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the battery of the present invention, and FIG. 2 is a diagram showing the temperature change characteristics of the battery with respect to ambient temperature. 1... Positive electrode can, 2... Negative electrode can, 3... Insulating packing, 4... Positive electrode, 6... Negative electrode, 8... Separator, A ₁ ,
_A2 , _A3 ...Battery of the present invention, B...Comparison battery.

Claims (1)

[Scope of Claims] 1. A negative electrode comprising a light metal as an active material, a positive electrode, and an electrolyte comprising a solvent and a solute, the solute being lithium perchlorate and LiCF ₃ SO ₃ (lithium trifluoromethanesulfonate). A non-aqueous electrolyte battery comprising two components. 2. The nonaqueous electrolyte battery according to claim 1, wherein the negative electrode active material is lithium or thirium alloy, and the positive electrode active material is manganese dioxide. 3. The non-aqueous electrolyte battery according to claim 2, wherein the solvent is a mixed solvent of propylene carbonate and 1,2 dimethoxyethane.