JPH0620704A - Hermetic seal liquid active material battery - Google Patents

Abstract

PURPOSE:To get a battery highly reliable on the operation of explosionproof function by providing a thin part at the bottom of a battery container, using oxyhalide of liquid for a positive active material, and alkaline metal or its alloy for a negative pole. CONSTITUTION:A compound 14 being liquid at normal temperature such as thionyl chloride, sulfuryl chloride, phospholi chloride, etc., is used for a positive active material. Li, Na, K, or alloy having these materials for its base material is used for a negative electrode. A thin part 4 is provided at the bottom 2 of a battery container 1. A wire gauze or a porous substance 5 of metal such as an expand metal, punching metal, etc., is arranged at the inside of the bottom, and the periphery is spot-welded to the inside of the bottom 2 of the container 1. The thin part breaks by the abnormal rise of the inner pressure of a battery, which prevents the bursting under high pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed liquid active material battery having an explosion proof function, and more particularly to a hermetically sealed liquid active material battery having an increased operational reliability of the explosion proof function.

[0002]

2. Description of the Related Art An oxyhalide that is liquid at room temperature, such as thionyl chloride, sulfuryl chloride, and phosphoryl chloride, is used as a positive electrode active material, and an alkali metal such as lithium, sodium, or potassium, or an alkali metal containing an alkali metal as a base material. In a so-called liquid active material battery using an alloy for the negative electrode, both the positive electrode active material and the negative electrode constituent substance are very likely to react with water, so in order to improve the degree of sealing, the sealing of the opening of the battery container containing them is performed. , A hermetically sealed seal is used.

By the way, the battery sealed by using the hermetic seal has an advantage that it has a high hermeticity and an excellent storability, but on the other hand, because of the high hermeticity, it is exposed to high temperature heating or high voltage. When you encounter an abnormal situation such as being charged with, the pressure inside the battery rises abnormally and the battery explodes, producing a loud popping sound.
Battery contents may scatter around and pollute battery-powered equipment.

Therefore, a cross-shaped thin portion is formed at the bottom of the battery container, and the thin portion is broken when the pressure inside the battery starts to rise abnormally, thereby preventing the battery from bursting under high pressure. Although it has a so-called explosion-proof function, in order to confirm the safety when it is accidentally thrown into a fire, a battery was put into a fire and a test was performed. Since the rising temperature is too high, the fractured portion is clogged with the positive electrode material mixture and the separator, and the battery has a drawback of bursting under high pressure.

[0005]

SUMMARY OF THE INVENTION The present invention solves the problem that the conventional hermetically sealed liquid active material battery bursts under high pressure when exposed to an abnormally high temperature, and enhances the operational reliability of the explosion-proof function. In addition, it is an object of the present invention to provide a hermetically sealed liquid active material battery having excellent safety.

[0006]

SUMMARY OF THE INVENTION The present invention achieves the above object by welding a metal porous body such as a wire mesh, expanded metal or punching metal to the inner surface of the bottom of a battery container having an explosion-proof thin portion on the bottom. It has been achieved.

That is, when the porous metal body is welded to the inner surface of the bottom of the battery container by spot welding or the like so as to cover the thin portion, the porous metal body can positively charge the positive electrode even when the battery is exposed to an abnormally high temperature. The separator and the separator are prevented from blocking the fractured portion of the thin portion, the explosion-proof function of the thin portion operates normally, and the safety of the battery is secured.

Next, a structural example of the hermetically sealed liquid active material battery of the present invention will be shown with reference to the drawings.

FIG. 1 is a sectional view showing an example of the hermetically sealed liquid active material battery of the present invention.

In FIG. 1, reference numeral 1 denotes a battery container. This battery container 1 is usually manufactured by drawing a stainless steel plate having a thickness of 0.2 to 0.5 mm into a cylindrical shape having a bottom, and a bottom portion 2 of the battery container 1 is formed. The central portion is projected to form a protruding portion 2a.

A groove 3 is formed in a cross shape at the protruding portion 2a of the bottom portion 2 of the battery container 1 to form a thin portion 4 for explosion protection in a cross shape.

The metal porous body 5 is arranged on the inner surface of the bottom of the battery container 1, and the outer peripheral portion of the metal porous body 5 is spot-welded to the inner surface of the bottom of the battery container 1. As the metal porous body 5, for example, wire mesh, expanded metal, punching metal, or the like is used.

Reference numeral 11 is a negative electrode, 12 is a separator, 13 is a positive electrode, 14 is an electrolytic solution, 15 is a positive electrode current collector, 16 is a battery lid, and the battery lid 16 comprises a body 17, an insulating layer 18, and a positive electrode terminal 19. , 20 is a bottom insulating material, and 21 is an upper insulating material.

The negative electrode 11 is obtained by forming a sheet of an alkali metal such as lithium, sodium, potassium or the like or an alkali metal alloy sheet containing the alkali metal as a base material into a cylindrical shape and pressing the sheet on the inner peripheral surface of the battery container 1. The separator 12 is made of glass fiber non-woven fabric and has a cylindrical shape.
And the cylindrical positive electrode 13 are separated.

The positive electrode 13 is composed of a so-called carbon porous molded body, which is a porous molded body of a material containing acetylene black as a main component and having carbon and a graphite and polytetrafluoroethylene as a main material. Are doing

The electrolyte solution 14 uses an oxyhalide that is liquid at room temperature, such as thionyl chloride, sulfuryl chloride, and phosphoryl chloride, which are positive electrode active materials, as a solvent.
It was prepared by dissolving a supporting electrolyte such as LiAlCl _{4 in} this oxyhalide. Since the oxyhalide of the positive electrode active material also serves as the solvent of the electrolytic solution, a large amount of electrolytic solution 14 is injected into the battery in this battery, unlike other batteries.

Further, as can be seen from the fact that the oxyhalide is the positive electrode active material, the positive electrode 13 does not react by itself, but is ionized and eluted from the oxyhalide of the positive electrode active material and the negative electrode 11. It becomes a reaction place with the lithium ion etc.

The positive electrode current collector 15 is made of a nickel rod, and the battery lid 16 has the body 17, the insulating layer 18, and the positive electrode terminal 19, as described above, and the body 17 is made of stainless steel. The raised outer peripheral portion is the battery container 1
It is joined by welding to the open end of the.

The insulating layer 18 is made of glass and has a body 1
7 is formed on the inner peripheral side, and the insulating layer 18 insulates the body 17 from the positive electrode terminal 19, and at the outer peripheral surface, the constituent glass is fused to the inner peripheral surface of the body 17, A so-called hermetic seal structure is adopted in which the constituent glass is fused to the outer peripheral surface of the positive electrode terminal 19 to bond and seal the body 17 and the positive electrode terminal 19.

The positive electrode terminal 19 is made of stainless steel, and a part of the positive electrode terminal 19 has a pipe shape when the battery is assembled and is used as an electrolyte injection hole. The upper end of the positive electrode terminal 19 is injected into the hollow portion after the electrolyte is injected. The upper part of the electric body 15 is welded and sealed.

The lower separator 20 is made of the same glass fiber non-woven fabric as the separator 12 and prevents the positive electrode 13 and the battery container 1 from coming into contact with each other. The upper separator 21 is made of the same glass fiber non-woven fabric as the separator 2,
The body 17 of the battery lid 16 that also serves as the negative electrode terminal is prevented from coming into direct contact.

In the battery of the present invention, as described above,
As the positive electrode active material, an oxyhalide such as thionyl chloride, sulfuryl chloride or phosphoryl chloride which is liquid at room temperature (25 ° C.) is used.

These oxyhalides are used as a positive electrode active material and also as a solvent for an electrolytic solution. The electrolytic solution contains these oxyhalides as LiAlCl ₄ and LiAl.
It is prepared by dissolving a supporting electrolyte such as Br ₄ , LiGaCl ₄ , LiB ₁₀ Cl ₁₀ . Incidentally, when the preparation of the electrolytic solution, presence of a supporting electrolyte LiCl and AlCl _3, such as LiAlCl ₄ in the form of LiAlCl ₄ in added to the oxyhalide electrolyte (however, Li ⁺ ions and AlCl ₄ to ionize ^- Present with Aeon)
You may do it.

[0024]

EXAMPLES Next, the present invention will be described more specifically with reference to examples.

Example 1 An outer diameter of 14 mm and a height of 50 mm with the structure based on FIG.
A thionyl chloride-lithium hermetically sealed liquid active material battery was prepared.

The battery container 1 is made of stainless steel, has a thickness of 0.3 mm, and has a groove 2 having an inverted trapezoidal cross section on the protruding portion 2a of the bottom portion 2 (however, the above shape is seen from the bottom side of the groove 3). Is formed in a cross shape, the thin portion 4 having a thickness of 0.09 mm is provided in a cross shape.

The metal porous body 5 has a mesh size LW3.
0 mm × SW 1.0 mm, W = 0.20 mm, t = 0.
Using 1 mm of nickel-made expanded metal, the expanded metal was punched into a circular shape having an outer diameter of 12.8 mm, arranged on the inner surface side of the bottom portion 2 of the battery container 1, and the periphery thereof was welded at 6 points.

The amount of lithium in the negative electrode was 530 mg, and the theoretical electric capacity of this lithium was 2047 mAh. The positive electrode acetylene black was 893 mg, the injection amount of the electrolytic solution was 4 ml, and the theoretical electric capacity of thionyl chloride as the positive electrode active material was about 2640 mAh.

Comparative Example 1 A battery having the same structure as in Example 1 was prepared except that the porous metal body 5 was not arranged on the inner surface side of the bottom portion 2 of the battery container 1.

Twenty batteries of the above-mentioned Example 1 and each of the batteries of Comparative Example 1 were put into a fire to examine whether or not the battery bursts in the fire. The results are shown in Table 1. In Table 1, the denominator in the "Number of batteries in fire burst" column indicates the number of batteries used in the test, and the numerator indicates the number of batteries that burst in fire.

[0031]

[Table 1]

As shown in Table 1, in Comparative Example 1 corresponding to the conventional product, 8 batteries out of 20 batteries burst during fire, but Example 1 of the present invention did not burst during fire. There was nothing that occurred, and the explosion-proof function of the thin portion 4 was operating normally.

[0033]

As described above, according to the present invention, the metal porous body is disposed on the inner surface side of the bottom of the battery container having the explosion-proof thin portion at the bottom, and the outer peripheral portion is the inner surface of the bottom of the battery container. It was possible to operate the explosion-proof function due to the thin-walled part with high reliability by fixing it by welding.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a hermetically sealed liquid active material battery according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery container 2 Bottom part 3 Groove 4 Thin part 5 Metal porous body 11 Negative electrode 12 Separator 13 Positive electrode 14 Electrolyte 16 Battery lid 17 Body 18 Insulating layer 19 Positive electrode terminal

Claims (1)

[Claims] 1. An oxyhalide that is liquid at room temperature, such as thionyl chloride, sulfuryl chloride or phosphoryl chloride, is used as a positive electrode active material, and an alkali metal such as lithium, sodium or potassium, or an alkali metal containing such an alkali metal as a base material. A hermetically sealed liquid active material battery that uses an alloy for the negative electrode and seals the opening of the battery container with a thin explosion-proof portion formed on the bottom with a battery lid equipped with a hermetic seal. A hermetically sealed liquid active material battery characterized by being welded.