JPH037885Y2 - - Google Patents

Description

[Detailed explanation of the idea] Industrial applications The present invention relates to molten salt batteries.

Conventional technology and its problems In molten salt batteries, the electrolyte is solid at room temperature.
Since the ionic conductivity is zero, electrical energy cannot be extracted, but when used, the heating element built into the battery is burned to melt the electrolyte, increasing the ionic conductivity and making it possible to extract electrical energy. This is what I did.

The eutectic mixtures of potassium chloride and lithium chloride, potassium bromide and lithium bromide, etc. used as electrolytes in molten salt batteries have strong hygroscopic properties, so they may cause damage to the welds between the battery case and lid and the terminals. The drawer must be completely airtight.

On the other hand, during use, the heating element is burned in a completely airtight battery case, so the temperature rise causes the internal pressure to rise, causing the battery case to expand and rupture, reducing reliability. For this reason, batteries are used that have thicker walls in the container and lid so that they can withstand the rise in internal pressure of the container, but these batteries have the drawbacks of low weight efficiency and high cost. It was hot.

Purpose of the invention The purpose of the present invention is to provide a molten salt battery with improved weight efficiency and reliability, which eliminates the above-mentioned drawbacks.

Structure of the invention The present invention increases the strength when welding the opening of the battery case and the periphery of the lid by making the wall thickness of the opening of the battery case thicker than the other parts.

EXAMPLE FIG. 1 is a sectional view of the molten salt battery of the present invention.
In FIG. 1, reference numeral 1 denotes a unit cell, which is laminated alternately with heating elements 2 in close contact with each other. The unit cell 1 includes an anode plate 3 made of calcium chromate, lead chromate, etc., an electrolyte layer 4 made of a eutectic mixture of potassium chloride and lithium chloride or a eutectic mixture of potassium bromide and lithium bromide, and an electrolyte layer 4 made of magnesium or calcium. The current collector plate 6 is made of nickel or iron. The heating element 2 is a sheet made of a thermite reaction mixture such as iron, potassium perchlorate, zirconium and barium chromate, and its combustion heat melts the electrolyte layer 4, increasing ionic conductivity and extracting electrical energy. I have to. Reference numeral 7 denotes an electric ignition ball for igniting the heating element 2, which is made of platinum-iridium alloy resistance wire coated with a mixture of tricinate and potassium perchlorate. 8 is a heat insulating material made of glass fiber and asbestos fiber. In the molten salt battery of the present invention, these battery elements are housed in a battery case 14, while terminals 10 and 11 extending from the battery elements and an ignition terminal 12 are placed in an airtight part 17 in a lid 9 made of iron or stainless steel. is attached through the peripheral part 1 of the lid 9.
3 and the opening 1 of the iron or stainless steel battery case 14
5 and is welded to each other through an airtight welded portion 16.

In the molten salt battery of the present invention, as shown in FIG. 1, the thickness of the opening 15 of the battery case 14 is made thicker than the other parts, thereby increasing the strength of welding through the airtight welding part 16 of the battery. The purpose is to increase the size without significantly increasing the weight so that it can sufficiently withstand the increase in internal pressure during use.

This will be explained in detail below using examples.

A comparison will be made between the battery of the present invention and a conventional battery whose case diameter and height are the same. The battery of this invention has a wall thickness of 1 mm at the opening and bottom of the battery case, and a wall thickness of 0.6 mm at other parts.
All conventional batteries have a case wall thickness of 1 mm. The weight of the battery case alone is approximately
The battery of the present invention is 35% lighter, and when the battery elements are housed to form a molten salt battery, the weight of the battery of the present invention can be reduced by about 7% compared to conventional batteries.

In the present invention, the thickness of the opening 15 and the dimensions of the thickened portion are not particularly defined.

Effects of the invention As detailed in the examples, the molten salt battery of the invention has high weight efficiency and high reliability that can sufficiently withstand internal pressure increases during use, and has extremely high practical value. be.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the molten salt battery of the present invention. 1...Battery, 2...Heating element, 8...Insulating material, 9
... Lid, 13 ... Peripheral part, 14 ... Battery case, 15 ...
...Opening portion, 16...Airtight welded portion, 17...Airtight portion.

Claims (1)

[Claims for Utility Model Registration] A battery element comprising a battery case 14 and a lid 9, in which unit cells 1 and heating elements 2 are alternately stacked and surrounded by a heat insulating material 8. A molten salt battery is housed in the battery case 14, and the opening 15 of the battery case 14 is thicker than the other parts, and the lid 9 has terminals 10, 11 and an ignition terminal 12 through an airtight part 17. is attached, and the terminal 1
0 and 11 are attached to the battery element, and the ignition terminal 12 is attached to the electric ignition ball 7 that ignites the heating element 2. are welded together by an airtight welding part 16, and the opening 15 of the battery case 14 is sealed.