Thermal battery and method of making the same having solid complex of SO2 and lithium tetrachloroaluminate as electrolyte

Abstract

A light weight, thermal battery having a cathode, an anode and a solid complex of SO.sub.2 and lithium tetrachloroaluminate as the solid electrolyte therein. The solid complex of SO.sub.2 and lithium tetrachloroaluminate is represented by the formula LiAlCl.sub.4.multidot.xSO.sub.2, wherein 1.0<x<4. The thermal battery is activated by heating the battery to temperatures of approximately between 35.degree. C. to 90.degree. C. A method of making the thermal battery is taught.

Description

FIELD OF THE INVENTIONThe present invention relates, in general, to a storage stable, primary or secondary, light weight, thermal battery that is heat activated by heating the battery to only approximately between 35.degree. C. to 90.degree. C. More particularly, the present invention relates to a thermal battery that employs a complex of sulfur dioxide and lithium tetrachloroaluminate as the electrolyte. Once heat activated, the thermal battery can remain active until it is completely discharged. No additional heating is needed. Moreover, the thermal battery of the present invention, once heat activated can be used at ambient and sub-ambient temperatures. A method of making the thermal battery is disclosed.BACKGROUND OF THE INVENTIONThermal batteries generally contain an active metal anode, a cathode and an electrolyte that is solid at normal, ambient temperatures. A current thermal battery, for instance, may comprise a lithium or lithium alloy anode, an FeS.sub.2 cathode and a LiC...

AI Technical Summary

Benefits of technology

It is an object of the present invention to provide a thermal battery which can be quickly activated by heating the battery to a temperature of approximately 35.degree. C. to 90.degree. C. so as to melt the solid electrolyte therein.

A further object of the present invention is to provide a thermal battery that may be activated more rapidly than prior art thermal batteries since less heating and consequently less heating materials are required to activate the battery than required by the prior art.

It is a further object of the invention to provide a thermal battery wherein once the cell electrolyte is brought to its molten state, additional or continuous heating of the electrolyte in order to maintain activation of the battery and completely discharge the battery is no longer needed regardless of how slowly the battery is discharged.

Still another object of the present invention is to provide a light weight, low temperature thermally activated electrochemical cell having extended storage shelf life.

Problems solved by technology

The need for such great quantities of pyrotechnic heating materials adds significantly to the overall weight and size of the thermal battery.

This is undesirable.

Moreover, once the thermal battery has been activated, it is often a problem maintaining the high temperatures needed to keep the electrolyte in its molten state until power is no longer needed.

In addition, heating the state of the art thermal batteries to such high temperatures in order to melt the electrolytes and activate the battery requires significant time.

This method can be time consuming and complex when one considers the various steps that are needed to be employed in preparing the individual component materials and in the pressing of the various component parts to form the final battery product.

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