JPS5947432B2 - organic solvent battery - Google Patents

Description

Detailed Description of the Invention The present invention uses alkali metals such as lithium and sodium as the negative electrode, uses an electrolytic solution using an organic solvent that does not dissolve these metals, and uses phosphorus pentoxide as the positive electrode active material. It concerns energy density batteries.

Conventionally, batteries that use an alkali metal such as lithium or sodium as a negative electrode and an organic electrolyte have been studied for various positive electrode active materials because high voltage and high energy density can be obtained by using an appropriate positive electrode active material. .

Typical of these are Cl゛2, NiF
2. Metal halides such as cUct3Agct, Cr
There are metal oxides such as 2O3, cu2o2MnO2, and MoO3, and interlayer compounds such as (CF)n.

However, there were many cases in which discharge performance was poor due to large self-discharge and large polarization, and there were problems with the safety of the positive electrode active material itself.

'The present invention is based on the fact that, as a result of investigating various new active materials in order to obtain a positive electrode superior to conventional ones, it was discovered that phosphorus pentoxide is particularly superior. Although phosphorus pentoxide has very high hygroscopicity and is easily decomposed by moisture, it leaks easily into the electrolyte, has low solubility, and is chemically stable.

Furthermore, the actually measured open circuit voltage when combined with a lithium negative electrode was 3.8V. According to the discharge capacity, the discharge reaction is a 4-electron reaction, and the battery reaction formula is P2O5+ 4Li→P203+ 2
With Li20, the positive electrode is p2o5+4e-→P203+20
It is 2-.

The theoretical energy density at this time is 3.911wh/cc
Therefore, if moisture is treated sufficiently, it can be expected that a battery with high voltage and high energy density can be obtained. Table 1 shows a comparison with conventional positive electrode active materials in terms of open circuit voltage and energy density. Next, the embodiment of the present invention will be described as 24.5-φ×
The case where 2.5□ is assembled into a coin battery will be explained based on the drawings.

In Fig. 1, 1 is a positive electrode mixture consisting of a positive electrode active material of phosphorus pentoxide and 10% graphite as a conductive material, and is placed in a positive electrode can 2 with a diameter of 201 mm at a pressure of 2 tons/Cii.
! , formed to a thickness of 1.511 mm and filled.

This positive electrode mixture 1 was prepared by mixing phosphorus pentoxide, which had been sufficiently dried in a high vacuum to remove moisture, with graphite, which had also been dried in a high vacuum, in an argon atmosphere dry box with a moisture and oxygen content of 5 to 6 degrees. It is something. Other battery assembly operations were also performed in the dry box. Reference numeral 3 denotes a separator made of a polypropylene non-woven fabric, on which an electrolyte layer was formed by impregnating a propylene carbonate organic electrolyte solution containing 1 mol of LictO4 as an electrolyte.

4 is a lithium negative electrode active material.

5 is a negative electrode sealing plate, and 6 is a packing.

FIG. 2 is a comparison diagram showing the characteristics of terminal voltage with respect to discharge capacity when the battery shown in the embodiment of the present invention shown in FIG. 1 and the conventional battery are discharged with a constant resistance of 30 KΩ.

Curve A is a discharge curve when phosphorus pentoxide according to the present invention is used as the positive electrode active material, curve B is a discharge curve when manganese dioxide is used, and curve C is a discharge curve when carbon fluoride is used.

Table 2 shows that the discharge capacity per unit volume is determined based on the discharge curve in Figure 2, and the battery of the present invention has a discharge capacity per unit volume of approximately 35 to 55% compared to the conventional battery.
It can be seen that there is an improvement of 0%. As described above, the battery using phosphorus pentoxide of the present invention has a higher terminal voltage and a higher discharge amount per unit volume than conventional batteries, and has extremely high industrial value.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an organic solvent battery in an example of the present invention, and FIG. 2 is a comparison diagram of discharge characteristics between the battery of the present invention and a conventional battery. 1...Positive electrode mixture, 2...Positive electrode can, 3.
... Separator, 4 ... Negative electrode active material, 5
...Negative electrode sealing plate, 6... Packing.

Claims (1)

[Claims] 1. In a battery comprising a negative electrode active material made of an alkali metal such as lithium or sodium, a positive electrode active material, and an organic solvent electrolyte, the positive electrode active material is phosphorus pentoxide (P_2O_5) from which water has been removed. An organic solvent battery featuring: