JPH0675399B2 - Non-aqueous electrolyte battery - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a non-aqueous electrolyte provided with a negative electrode using lithium or a lithium alloy as an active material, a non-aqueous electrolyte, and a positive electrode using cupric oxide as an active material. The present invention relates to an electrolytic solution battery.

(B) Conventional technology A non-aqueous electrolyte battery using lithium or a lithium alloy as a negative electrode active material and cupric oxide as a positive electrode active material is disclosed in, for example, Japanese Patent Publication No.
-31326 publication, the battery voltage is about 1.5.
Since it is about V, it has an advantage that it can be used interchangeably with a silver oxide battery or a mercury battery, which are commonly used as a power source for electronic devices.

(C) Problems to be solved by the invention In this type of battery, a high voltage is shown at the initial stage of discharge due to impurities such as iron, silicon and manganese in the positive electrode and active parts. Therefore, there is a problem that the open circuit voltage gradually rises during storage although the measures are taken by preliminary preliminary discharge.

Further, there is a problem that the impurities or active portions are dissolved in the electrolytic solution and are deposited on the negative electrode to increase the internal resistance with storage.

D. Means for solving the problem Cuprous oxide treated with sulfite is used as the positive electrode active material. A typical example of sulfite is sodium sulfite (Na2S
O3) or sodium bisulfite (NaHSO3).

The mechanism of high voltage due to impurities or active parts in the positive electrode for operation is considered as follows. That is, when impurities such as metals such as iron, silicon and manganese are in the form of oxides, or the presence of active moieties, for example copper peroxide such as Cu2O3. According to the present invention, since the sulfite for treating cupric oxide is a deoxidizing reducing agent, it is possible to suppress the change of impurities into oxides, and to make the active portion low in activity.

Further, although the reason is not known, sulfite can suppress the dissolution of impurities in the electrolytic solution, and can suppress the increase in internal resistance due to the precipitation of impurities on the lithium negative electrode.

F. Examples Hereinafter, examples of the present invention will be described in detail.

Commercial grade of cupric oxide in 1 mol / Na2SO3 aqueous solution
Soak for 72 hours, then wash with water and dry. To 85% by weight of the treated cupric oxide, 10% by weight of graphite as a conductive agent and 5% by weight of fluororesin powder as a binder were added and mixed sufficiently, and the mixture was pressurized at a pressure of about 2 ton / cm ³ . Pressure molded with
We obtained a molded product with a thickness of 15.0 mm and a thickness of 1.1 mm.
Heat treatment is performed at a temperature of 0 ° C. to obtain a positive electrode.

The negative electrode is obtained by rolling a lithium plate to a thickness of about 0.6 mm and punching this rolled lithium plate to a diameter of 15.0 mm. The electrolyte used is a mixed solvent of propylene carbonate and 1.2-dimethoxyethane in which 1 mol / liter of lithium perchlorate is dissolved, and the separator is made of polypropylene non-woven fabric and has a diameter of 20.0 mm and a thickness of 2.5 mm (A). It was created.

Then, in order to examine the superiority of the battery of the present invention, a comparative battery (B) similar to the battery of the present invention was prepared except that cupric oxide was not treated with sulfite.

FIG. 1 shows changes in open circuit voltage over time when these batteries were previously discharged at 5% of the theoretical capacity and then stored under conditions of temperature 60 ° C. and humidity 90%. From FIG. high temperature,
It can be seen that the storage characteristics under high humidity are improved.

Also, FIGS. 2 and 3 show the relationship between the concentrations of Na2SO3 and NaHSO3 as sulfites and the open circuit voltage, respectively, and FIGS. 4 and 5 similarly show the concentrations of Na2SO3 and NaHSO3 and the internal resistance. Show the relationship.

It is understood from FIGS. 2 to 5 that the concentration of Na2SO3 is preferably in the range of 1 to 3 mol /, and the concentration of NaHSO3 is preferably in the range of 1 to 4 mol /. 2 to 5 show a temperature of 60.
These are the measurement results after storage for 50 days at a temperature of 90 ° C and a humidity of 90%.

As described above, in the non-aqueous electrolyte battery using lithium or a lithium alloy as the negative electrode active material and cupric oxide as the positive electrode active material, by using cupric oxide treated with sulfite, this type of battery It can improve the storage characteristics of and its industrial value is extremely large.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the open circuit voltage of the battery and the storage period, FIGS. 2 and 3 are diagrams showing the relationship between the sulfite concentration and the open circuit voltage of the battery, FIG. 4 and FIG. FIG. 4 is a diagram showing a relationship between sulfite concentration and internal resistance of a battery. (A) ... Invention battery, (B) ... Comparison battery.

Claims (2)

[Claims] 1. A non-aqueous electrolyte battery comprising a negative electrode containing lithium or a lithium alloy as an active material, a non-aqueous electrolyte solution, and a positive electrode containing cuprous oxide treated with sulfite as an active material. 2. The non-aqueous electrolyte battery according to claim 1, wherein the sulfite is sodium sulfite or sodium hydrogen sulfite.