JPS58121563A - Inorganic electrolyte battery - Google Patents

Abstract

PURPOSE:To prevent bulging and decrease of performance of a battery by installing a space equivalent to 10-30% of electrolyte volume inside the battery in an inorganic electrolyte battery. CONSTITUTION:In the figure, 1 is a negative electrode comprising lithium, 2 is a separator of glass fiber nonwoven fabric, and 3 is a positive electrode consisting of a carbon porous molding body. An electrolyte obtained by dissolving 1.8mol/l aluminum lithium chloride in thionyl chlorideis is used. Thionyl chloride also acts as a cathode active mass. A space is usually installed between a seal and a power generating element, that is, in the place indicating by 8. In a battery having a space of 10% volume ratio to the electrolyte, little bulging due to expansion of the electrolyte appeares. When volume ratio is 30% or less, discharge capacity is almost same as that of conventional battery.

Description

Detailed Description of the Invention The present invention provides thionyl chloride (soci2), sulfuryl chloride (SO2C12), phosphoryl chloride (PoC16)'z
The purpose of this invention is to improve an inorganic electrolyte battery that uses D oxyhalide as the electrolyte solvent and positive electrode active material and an alkali metal as the negative electrode active material, and to provide an inorganic electrolyte battery that can be used even at high temperatures.

Inorganic electrolyte batteries, which use oxyhalides such as thionyl chloride as the electrolyte solvent and positive electrode active material, and alkali metals as the negative electrode active material, have higher energy density and excellent low-temperature characteristics than other types of batteries. It has been attracting a lot of attention lately.

In this battery, a metal lid with a glass seal is inserted into the opening of the battery container containing the power generation element, and the inner surface of the opening local wall of the battery container and the outer circumferential surface of the metal lid are welded together, a so-called hermetic seal. Because it has a sealed structure, it has the feature of not leaking even under harsh conditions, so users can use this battery at temperatures of 85 to 100 degrees.
There have been requests for use at high temperatures such as C.

However, when batteries with conventional structures are used at such high temperatures, the battery container bulges, and in some cases, the welded portion between the battery container and the metal lid may peel and explode.

The inventors of the present invention have conducted various studies to investigate the cause of such battery swelling and to find measures to prevent it, and have found that battery swelling under such high temperatures is caused by the expansion of the electrolyte. and that there is 1 part of the electrolyte in the battery.
They discovered that when a space corresponding to a capacity of 0 to 30 is provided, an inorganic electrolyte battery can be obtained that does not cause blistering even when used at high temperatures and reduces battery performance. Ta.

In other words, in this battery, the oxyhalide as the electrolyte solvent also works as the positive electrode active material, so a much larger amount of electrolyte is injected than in other systems, so
The expansion of the dissolved solution causes a significant increase in volume, which causes the battery to swell, so providing a space of a specific volume within the battery prevents the battery from bulging and also prevents the battery performance from deteriorating.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partial sectional view showing the structure of an inorganic electrolyte battery according to the present invention. In the Hx diagram, (1) is a negative electrode made of lithium, (2) is a separator made of glass fiber nonwoven fabric, and (3) ) is a positive electrode made of a carbon porous molded body. (4) is a positive electrode current collector made of stainless steel;
5) is a negative electrode can used as a battery container made of stainless steel. (6) is a metal lid made of stainless steel or the like, the outer periphery of this metal lid (6) is welded to the inner periphery of the opening of the negative electrode can (5), and the inner periphery of the extended metal lid (6) is Glass seal (
7) is formed, and the electrolyte is injected into the glass seal (7) through the metal pipe (9) which has been previously welded to the VC, and then the positive electrode current collector (4) and the metal pipe (<9) are welded to complete the battery. The inside has a sealed structure. The electrolytic solution for this battery is a solution prepared by dissolving lithium aluminum chloride in thionyl chloride at a ratio of 1.8 mol/l, and the thionyl chloride also functions as a positive electrode active material. The positive electrode (3) is formed by adding polytetrafluoroethylene as a binder to acetylene black, and (l()) is a separator paper made of the same material as the separator.

In the battery having the configuration shown in FIG. 1, the volumes of the constituent members are changed as shown in Table 1.
Six types of F batteries were manufactured.

These six types of batteries were left at 100° C. for 48 hours, and the bulge that occurred at the bottom of the negative electrode can (5) was measured using a shape measuring machine. In addition, six types of batteries manufactured as described above were heated at 20"C.
Discharge at a constant current of 110 mA, and the final voltage is 2. The discharge capacity up to OV was measured.

FIG. 2 shows the relationship between the swelling and discharge capacity of the battery measured as described above and the volume ratio (correspondence) of the space to the electrolyte.

Note that the linear volume in Table 1 is the volume inside the negative electrode can excluding the lid, and the space is the volume of the negative electrode, positive electrode, separator, isolation paper, positive electrode current collector, and electrolyte solution calculated from the linear volume. This refers to the part that has been deducted. This space is usually mainly provided between the lid portion and the power generation element in FIG. 1, that is, at the position indicated by (8).

As shown in Figure 2, the volume ratio [(
Blistering is observed in batteries A and B with space/electrolyte (X 100), but almost no blistering is observed in battery C, where the volume ratio of space to electrolyte is increased to 10%, and even when the volume ratio is further increased. battery, E, F
No blistering was observed at all. On the other hand, the discharge capacity of Battery F, in which the volume ratio of space to electrolyte solution was increased to 85%, was considerably lower than that of the conventional battery, but in Battery E, where the volume ratio was 30%, there was almost no change.

In this manner, by providing a space corresponding to 10 to 30 volumes of electrolyte within the battery, blistering under high temperatures can be prevented without impairing the discharge performance of the conventional battery.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view of an inorganic electrolyte battery according to the present invention, and FIG. 2 is a diagram showing the relationship between the volume ratio of space to electrolyte (ch), swelling of the battery, and discharge capacity. (1)...Negative electrode, (3)...Positive electrode, (8)...
・Spatial patent applicant: Hitachi Maxell Co., Ltd.

Claims (1)

[Claims] 1. In an inorganic electrolyte battery in which an oxyhalide such as thionyl chloride, sulfuryl chloride, or phosphoryl chloride is used as an electrolyte solvent and a positive electrode active material, and an alkali metal is used as a negative electrode active material, 10 to 30% of the electrolyte is contained in the battery. An inorganic electrolyte battery characterized by having a space corresponding to .