And several diethyl ether electrolytes have been characterized for their usefulness in rechargeable cells. This characterization has involved extended room temperature cell cycling at various depths of discharge, evaluation of rate/capacity behavior of cells at 25° and −10°C, and storage of cells at 50°C for up to one month with subsequent cycling. The thermal stability of the electrolytes at 71°C was evaluated by storage experiments in sealed tubes, followed by product analysis. The performance of cells far surpassed the others. The present data further substantiate previous reports from this laboratory of the superior behavior of solutions in rechargeable Li cells. The electrolytes are too unstable thermally to be of practical use.