JPS59158073A - Nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To improve the flatness of the discharge voltage of a nonaqueous electrolyte battery as well as the duration in the last stage of the discharge of the battery by using a light metal represented by Li or Na as a negative active material and using beta-type MnO2 obtained through wet treatment as a positive active material. CONSTITUTION:A sheet consisting of a light metal represented by Li or Na metal used as a negative active material 4, is pressed and fixed on a negative plate 3. A positive mixture 6 containing beta-type MnO2 obtained by subjecting gamma-type MnO2 to wet treatment as a positive active material, is brought into close contact with a positive electrode 7. After that, a nonwoven fabric separator 5 containing nonaqueous electrolyte is interposed between the negative and the positive active material 4 and 6 to constitute a battery. By using such a positive active material, the discharge duration in the last stage of the discharge of the battery is widely improved.

Description

Detailed Description of the Invention The present invention provides non-aqueous electrolysis using light metals such as lithium and sodium as the cathode active material, manganese dioxide as the anode active material, and a non-aqueous organic solvent that does not oxidize the light metals as the electrolyte. 'fLt pond improvement.

It is widely known that manganese dioxide is effective as an anode active material for non-aqueous electrolyte batteries.

However, when γ-type mandioxide, which has traditionally been used for manganese batteries, is used as an anode active material for non-aqueous electrolyte batteries, the discharge time is not long enough, and the voltage flatness during discharge is also poor. This results in the following result. Therefore, it has been proposed that these γ-type manganese dioxide be used after being heat-treated, but if the heating temperature is too low, the manganese dioxide obtained by heat treatment will remain in the γ-type, and if the heating temperature is 450°C. Manganese dioxide obtained by processing at higher temperatures becomes β-type, but part of its surface is Mn2.
Phenomena such as reduction to O3 easily occur (there was a drawback that it was difficult to exhibit good battery performance. Therefore, the heat treatment was carried out in a narrow temperature range of around 400 ° C. It was believed that the beta-gamma type two-ferromagnetic manganese exhibited the best battery performance.

However, the utilization rate of manganese dioxide is not so high even when it is used as a β-γ type diacid manganese dioxide polar active material obtained by such conventional heat treatment (also, the flatness of the voltage at the end of discharge It was also pretty bad.

The present inventors have improved the above-mentioned problems with manganese dioxide as a conventional anode active material, and have achieved a flatness of the voltage during discharge and a large extension of the duration at the end of discharge. In the process of conducting various studies with the aim of providing a non-aqueous electrolyte battery, we decided to apply wet processing, which had previously been considered completely out of the norm and had not been considered as a manufacturing method for the anode active material of a non-aqueous electrolyte battery. As a result, an extremely useful β-type anode active material can be obtained, and a non-aqueous electrolyte battery using this material can achieve the above-mentioned pseudophase problem.

The invention was completed based on these findings.

That is, the present invention relates to a nonaqueous electrolyte battery in which a light metal such as lithium or sodium is used as a cathode active material and manganese dioxide is used as an anode active material, and the anode active material is wet-treated to form β-type manganese dioxide. It is characterized by:

As the cathode active material in -P6 of the present invention, light metals represented by lithium, sodium, etc. are used, and sheet-like materials of these are suitably cut and applied.

Further, as the nonaqueous electrolyte, a nonaqueous organic solvent that does not oxidize the light metal that is the cathode active material is used.

Specifically, -9i is obtained by dissolving lithium peroxide in a mixed solvent of propylene carzenate and 1,2-dimethoxyethane.

In the present invention, the manganese dioxide used as the positive electrode active material is made into the β type by wet-processing the γ type mancan dioxide. Wet processing in the present invention refers to γ
type manganese dioxide powder with divalent manganese ions and/or
Alternatively, the key is to create manganese dioxide lumps that are macroporous and strong by immersing them in a sulfuric acid bath containing magnesium ions. Next, the obtained lumps are coarsely crushed and sized to an appropriate particle size, and then washed with water and hot water in order to deoxidize and wash away residual impurities. If the temperature of this hot water washing is too low, the removal of impurities will be incomplete.

In addition, &1 of acid melting in which manganese dioxide powder is immersed
．． The temperature should be as high as possible and below the boiling point of the i-liquid.
It is more preferable that the immersion time be negative.

By such wet treatment, good β-type manganese dioxide can be obtained. This β-flooded manganese dioxide is then pressure-molded together with a conductive material and a slag paste, and is applied as a primary polarization mixture for non-aqueous electrolyte batteries.

Next, the advantages of the present invention will be explained in more detail with examples.

Examples include manganese ions of 2 og//J and magnesium ions of zofi/11. A sulfuric acid acidic bath containing -009/l of sulfuric acid was kept at 90°C, powdered manganese dioxide was immersed in this bath, and the bath was kept at 90°C and allowed to stand for 6 days to form solid manganese dioxide lumps. I got something. This lump was coarsely crushed and granulated to an appropriate particle size, washed with water, and washed with hot water (9
0''C), and after drying, the particles were sized to obtain β-type manganese dioxide.

The X-ray diffraction diagram of this β-type mankan dioxide is shown as A1 in FIG. For comparison, the X#1 diffractograms of conventional γ-type mankan dioxide and β-γ-type mankan dioxide obtained by heat treatment are shown in FIG. 1 as JIEi 2 and A3, respectively. As can be seen in FIG. 1, the β-type dazzling manganese according to the present invention has a large peak around 36°, and the overall peak is high and sharp.On the contrary, the β-γ type of A3 The peak around 6°·manganese dioxide is gentle and not so bright <4, and the peak around 36° for γ-type ma/can dioxide in 7·n2 is all (seeing 1", 28°( Near 1 (peak appears).

In addition, in Figure 2, the residual moisture of β-type mankan dioxide when heated and dried at 300°C is shown as person 1 in the figure. In addition, A2 in the figure
indicates the residual water content of β-type manganese dioxide. The residual moisture content of each sample was measured using the Karl Fischer method, and the results are expressed as changes over time. From this $2 figure, the β-type manganese dioxide in the present invention has a low water content of 2 to 3% even before drying, which is considered to be the most harmful in non-aqueous electrolyte batteries, and the drying time is short. Moreover, the moisture content after drying is low. In this way, in order to prepare the anode active material for non-aqueous electrolyte batteries, which is the most sensitive to moisture, a wet process was carried out, which was completely unthinkable with conventional wisdom, and the resulting carbon dioxide Manganese is in the beta form,
By using this β-type manganese dioxide, battery performance is greatly improved.

Next, β-type mancan dioxide obtained as described above
．． 135 g of graphite 0091 and tetrafluoroethylene resin O, 061 were mixed and pressure molded at 3 t/d to prepare an anode mixture. In addition, use pre-dried manganese dioxide, pyrolead, and ethylene tetrachloride resin (・
Ta. A test cell as shown in FIG. 3 was prepared using the obtained anode mixture, and a continuous discharge test of 2.5Ω was conducted at room temperature at 20°C. All of the above operations were performed in a docu-dex under an argon atmosphere.

Denpeisho is) 1:1 of ``propylene carnate, 1,2-dimethoxyethane'' (1:1 of lithium perchlorate to the combined bath medium)
A mol/l solution was used. The reagents used in this case were dried by a conventional method. Also,
The cathode was used by punching out a sheet of metal lithium to have the same diameter as the anode mixture.

In the 31st cell, 1 is a cathode terminal for extracting current to the outside, and 2 is an insulator made of Teflon resin, each of which is screwed in to seal the cell. 3 is a cathode plate, 4 is a pressed metal lithium sheet,
Reference numeral 5 indicates a separator made of nonwoven fabric, 6 indicates an anode mixture prepared by the method described above, and 7 indicates an anode made of stainless steel.

The results of the discharge test are shown in Figure 4. AI in the figure is Example 1
The results of the discharge test of the battery are shown. In addition, A2 uses β-type manganese dioxide that has been dehydrated at 250°C to avoid changes in crystal form, and Ya3 uses β-type manganese dioxide at 38°C.
Same as in Example 1 except that β-β type manganese dioxide obtained by heat treatment at 0°C was used as the anode mixture.
This figure shows the results of a battery prepared according to IoJ and a discharge test performed under the same conditions.

From this FIG. 4, the dragon according to Example 1? 114 compares 1
Compared to No. 1, the duration at the end of the release period is greatly extended, and the voltage of the release shell is also better in flatness, and it has extremely good battery characteristics as a non-aqueous electrolytic cell. It was something like that.

Example 2 β-type manganese dioxide was obtained using a sulfuric acid bath having the same composition as in Example 1 except that it contained magnesium ions. In the same manner as in Example 1, this β-type disaponified mancan was used as the positive electrode active material to prepare a positive compensation mixture, and a lithium Kameike test cell was constructed. This was heated at 20℃ and 2.5K.
As a result of continuous discharge of Ω, the discharge time to reach the final voltage of 2.1 V was 28.1 hours. On the other hand, as a comparative example, the discharge time of a test cell in which β-γ type manganese diferent obtained by conventional heat treatment (treated at 380° C.) was used as the anode active material was 23.8 hours.

From this, it was confirmed that β-type manganese dioxide obtained in a sulfur bath containing no magnesium ions also had excellent performance.

Example 3 β-type manganese dioxide was obtained using a sulfuric acid bath having the same composition as in Example 1 except that it did not contain manganese ions.

A test cell was constructed using this β-type manganese dioxide in the same manner as in Example 1, and continuous discharge was performed at 20° C. and 12,5 KΩ.

As a result, the final voltage 2. Discharge time to lV is 27.0
It was time. At the same time, for comparison, is β-type manganese dioxide active as an anode? A test cell of 2I quality was fabricated and discharged, and the discharge time was 162 hours.

As shown in the examples above, the β-type manganese dioxide obtained by each of the above methods exhibits extremely good battery performance that could not be obtained with conventional β-γ type or γ-type manganese dioxide. , its industrial value is tremendous.

[Brief explanation of the drawing]

FIG. 1 is a Xi diffraction pattern of each German manganese dioxide. FIG. 2 is a diagram showing the relationship between TA whistle moisture and bed time during heating dehydration of each spear manganese dioxide in FIG. 1. FIG. 3 is a schematic cross-sectional view of a test cell according to an embodiment of the present invention. FIG. 4 is a discharge curve diagram of the test cell in Example 1 of the present invention. 1... Cathode terminal 2... Insulator 3... Shadow
Electrode plate 4...Lithium 5...Separator
6°゛・Anode mixture bowl 1 recess 20 Number of electric bamboos, Negashi υfTNI (Ginma)

Claims (1)

[Scope of Claims] 1. In a nonaqueous electrolyte battery in which a light metal such as lithium or sodium is used as a cathode active material and manganese dioxide is used as an anode active material, the anode active material is wet-treated to form β-type manganese dioxide. A non-aqueous electrolyte battery that is characterized by the fact that it is 2 Claims in which the wet treatment consists of sizing a lump obtained by immersing manganese dioxide powder in a sulfuric acid acidic bath containing divalent manganese ions and/or magnesium ions, and washing with water and hot water. The non-aqueous electrolyte 1E pond described in item 1.