Method of making a teflon bonded cathode for use in a high temperature cell and high temperature cell including said cathode

Abstract

A method is provided for preparing flexible, free standing electrodes for use in preparing transition metal sulfide cathodes for use in high temperature electrochemical cells. Specifically, the cells contain sodium as the anode, a solid electrolyte separator of β"-Al 2 O 3 , and a Teflon bonded iron (IV) sulfide cathode emmersed in a molten salt electrolyte of NaAlCl 4 and electrochemically operated at 200° C.

What is claimed is: 
     
       1. A high temperature electrochemical cell including sodium as the anode, a solid electrolyte separator of B"-Al 2  O 3  ', and a Teflon bonded iron (iv) sulfide cathode emersed in a molten salt electrolyte of NaAlCl 4  and capable of being electrochemically operated at 200° C., wherein the teflon bonded cathode is obtained by a method including the steps of: (A) forming a mixture of about 80 weight percent FeS 2  as the active cathode component, about 10 weight percent graphite as the conductive diluent, and about 10 weight percent Teflon as the cathode binder,   (B) drop wise adding a wetting agent of distilled water-isopropylalcohol (60/40 weight percent) solution to the mixture to form a stiff dough,   (C) roll pressing the dough onto a expanded metal grid current collector and sintering at about 280° C. for about one hour under vacuum, and   (D) cooling under vacuum to ambient temperature.