Importance

Loading Importance Indicators...

Abstract

Method is provided for preparing a stabilized rechargeable cell having a negative electrode and a molten salt electrolyte (MSE) while avoiding problems of chloroaluminate cell systems which are not air stable. The cell of the present invention thus employs an LiBF.sub.4 /EMI.sub.BF4 MSE and a negative electrode of an inert substrate. On charging such cell, Li metal plates out on the electrode, which metal would immediately be attacked by such MSE. However a small amount of water is added to the MSE which, forms a lithium salt on the surface of such metal and protects it from attack by the MSE. However such protective film is permeable to Li.sup.+ ions. This means that on continuing to charge such cell, the LI.sup.+ ions flow from the MSE through the protective film and build up as more Li metal on the negative electrode, under the protective film. On discharge of such cell, the Li metal becomes Li.sup.+ ions which can pass through the protective lithium salt film. Accordingly employing a suitable cathode, the rechargeable cell of the invention can operate at high voltage, with a cycling efficiency of over 60%. Also the electrolyte of such cell has a variable temperature range, a high inherent conductivity and is air stable.

Loading the Abstract Image...

First Claim