JPH0624119B2 - Non-aqueous electrolyte battery - Google Patents

Description

Detailed Description of the Invention a. INDUSTRIAL APPLICABILITY The present invention is a primary device including a negative electrode whose active material is a light metal such as lithium and sodium, a positive electrode whose active material is a metal oxide, sulfide, or halide, and a non-aqueous electrolyte. Alternatively, it relates to a secondary battery.

B. 2. Description of the Related Art In a battery of this type, a so-called austenitic stainless steel having a nickel content of about 3 to 20% by weight is used as a material for a positive electrode constituent member that comes into direct or indirect contact with a positive electrode active material, for example, a positive electrode can or a positive electrode current collector. Is generally used, the constituent metal of the positive electrode can and the positive electrode current collector, which are electrically connected to the positive electrode during storage of the battery, are dissolved in the electrolytic solution and are deposited on the negative electrode to increase the internal resistance. Moreover, in extreme cases, a perforation phenomenon may occur. This cause is considered to depend on the amount of nickel contained in stainless steel, and was more remarkable as the amount of nickel increased.

Therefore, for example, as disclosed in Japanese Examined Patent Publication No. 55-15067, the positive electrode component contains almost no nickel,
It was proposed to use ferritic stainless steel, which is less susceptible to cracking under stress, but in this case as well, a dissolution phenomenon of the positive electrode constituent member was observed when it was stored at high temperature for a long time.

Since this type of battery has a smaller self-discharge than conventional silver batteries and alkaline batteries, it can withstand long-term use.Therefore, in recent years, due to the development of electronics on the equipment side, a small current There has been a demand for stable discharge characteristics over a long period of time. The minute current described here is at most several μA, but in order to obtain stable discharge characteristics for a long period of time under such minute current discharge, high reliability of the battery itself is required.

Also, in recent years, the development of secondary systems for non-aqueous electrolyte batteries has been active, and when charging the positive electrode constituent members and the metal ions forming the positive electrode are deposited on the negative electrode to form a passive film, the negative electrode is charged and discharged. Since the efficiency is lowered and the cycle characteristics are deteriorated, it is difficult to dissolve, in other words, a positive electrode constituent member having excellent corrosion resistance is required.

C. DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In a primary or secondary battery provided with a non-aqueous electrolyte, it is intended to suppress deterioration of battery characteristics due to dissolution of a positive electrode constituent member during high temperature storage or charging. .

D. Means for Solving Problems 0.5 to 10.0% by weight of aluminum as a positive electrode constituent member,
It is characterized by using stainless steel containing 0.1 to 10.0% by weight of titanium.

Here, stainless steel means Fe-Cr or Fe-C.
It is an alloy mainly composed of r-Ni and has a composition of Fe-
Cr system contains 11 to 30% of Cr, and Fe-Cr-N
The i-based alloy contains 9 to 26% of Cr and 4 to 26% of Ni.

E. Effect According to the present invention, aluminum is an inactive metal even at a noble potential and can suppress the dissolution (corrosion) phenomenon in terms of potential, and titanium is a metal that is very easily passivated, and titanium is an inactive state. Can be suppressed to dissolve stainless steel, and the synergistic effect of aluminum and titanium improves the corrosion resistance of stainless steel.

The content of aluminum is 0.5 to 10.
The effect is remarkable in the range of 0% by weight and 0.1 to 10.0% by weight in the case of titanium.

F. Embodiment An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 shows a half cross-sectional view of a battery. (1) is a negative electrode obtained by punching a rolled lithium plate into a predetermined shape and fixed to the inner surface of a negative electrode can (2) made of austenitic stainless steel (SUS304). It is pressure bonded to the negative electrode current collector (3). (4) is a positive electrode obtained by mixing manganese dioxide as an active material with carbon powder as a conductive agent and fluororesin powder as a binder at a weight ratio of 85: 10: 5, and molding this mixture. Therefore, it is pressed against the positive electrode current collector (6) that is fixed to the inner surface of the positive electrode can (5).

Here, the positive electrode can (5) and the positive electrode current collector (6) are made of aluminum.
It is composed of stainless steel containing 2.0% by weight and 2.0% by weight of titanium.

Incidentally, (7) is a separator impregnated with a non-aqueous electrolyte, and (8) is an insulating packing.

The table below shows a battery using various stainless steels as the positive electrode can and the positive electrode current collector, stored at 60 ° C for 3 months, and then at a frequency of 1KH
The internal impedance measured by z is compared, (A) is the battery of the present invention, (B) is a ferritic stainless steel containing almost no aluminum and titanium (SUS43).
0) shows the first comparative battery, and (C) shows the case of the second comparative battery using austenitic stainless steel (SUS304).

From the above table, it can be seen that the battery of the present invention has a low internal impedance after storage at high temperature and a small variation.
In addition, when the positive electrode can of each battery was observed with a scanning electron microscope after the measurement, corrosion was observed in the positive electrode cans of the comparative batteries (B) and (C), but corrosion phenomenon was observed in the positive electrode can of the battery (A) of the present invention. Was not recognized.

Figure 2 shows the titanium content when the aluminum content was 0.2%, 0.5%, 2.0%, 10.0% and 15.0% by weight, and the frequency of the battery after storage at 60 ° C for 3 months. The relationship with the average value of internal impedance when measured at 1 KHz is shown. From Fig. 2, the titanium content is 0.1-1
It can be seen that the internal impedance during storage at high temperature is low when the content of 0.0% by weight and the content of aluminum are in the range of 0.5 to 10.0% by weight.

Next, a charge / discharge test of these batteries (A), (B), and (C) immediately after preparation was performed.

Charge / discharge conditions are charging; 3.6 mA x 4 Hr, final voltage; 4.0
V, discharge; 3.0 mA, final voltage; 2.0 V.

From the results shown in FIG. 3, it can be seen that the cycle life of the battery (A) of the present invention is remarkably improved. After the charge / discharge test was completed, the battery was disassembled and the inside was observed. Comparative battery (B)
In (C), a brown deposit was found on the separator, and as a result of the analysis, a stainless component was found, but no deposit was found in the battery of the present invention.

Fig. 4 shows the relationship between the titanium content when the aluminum content is 0.2%, 0.5%, 2.0%, 10.0% and 15.0% by weight and the average cycle life in the charge / discharge test. Indicates. From Fig. 4, the titanium content is 0.
It was found that excellent cycle characteristics are exhibited when the aluminum content is in the range of 1 to 10.0% by weight and the aluminum content is in the range of 0.5 to 10.0% by weight, and the content of titanium and aluminum is the internal impedance at high temperature storage in Fig. 2. The same result was obtained.

G. EFFECTS OF THE INVENTION As described above, 0.5% aluminum is used as the positive electrode constituent member.
~ 10.0% by weight and 0.1-10.0% by weight of titanium are used to make positive electrode composition by the synergistic effect of aluminum which is stable against noble potential in non-aqueous electrolyte and titanium which is easy to passivate. Since it is possible to effectively suppress the dissolution of the member, in addition to high-temperature storage characteristics, it is possible to obtain a non-aqueous electrolyte battery having excellent cycle characteristics for secondary battery systems, and its industrial value is It is extremely large.

[Brief description of drawings]

FIG. 1 is a half sectional view of the battery of the present invention, FIG. 2 is a diagram showing the relationship between the titanium content and the internal impedance of the battery when the aluminum content is changed, and FIG. 3 is a comparison of the cycle characteristics of the battery. FIG. 4 and FIG. 4 are views showing the relationship between the titanium content and the number of battery cycles when the aluminum content was changed. (1) …… Negative electrode, (2) …… Negative electrode can, (3) …… Negative electrode current collector,
(4) …… Positive electrode, (5) …… Positive electrode can, (6) …… Positive electrode current collector,
(7) …… Separator, (8) …… Insulating packing.

Claims (1)

[Claims] 1. A positive electrode component comprising a negative electrode using a light metal such as lithium or sodium as an active material, a non-aqueous electrolyte, and a positive electrode, and 0.5 to 10.0 parts by weight of aluminum is used as a positive electrode constituent member that is in direct or indirect contact with the positive electrode active material. %, Titanium 0.1 to 10.0% by weight stainless steel is used, a non-aqueous electrolyte battery.