Pelletized lithiummetal sulphide cells part II. Some operating characteristics of pelletized LiAlFeS cells

Abstract

A number of small, pelletized LiAl/FeS secondary cells, in which the LiClKCI electrolyte is immobilized on the surface of an inert ceramic powder, have been tested over a range of operating conditions. The capacity of such cells is markedly dependent on both cell temperature and discharge current density, an effect attributed to local compositional changes in the binary electrolyte mixture. Measurements of cell resistance and electrolyte reequilibration phenomena lend support to this argument. The self-discharge rate of cells left on open-circuit was found to be relatively high and sensitive to moisture contamination. The cycle life of these cells, however, is remarkably good, more than 2000 charge/discharge cycles having been completed at a one-hour rate. In such experiments the current efficiency was found to approach 100% and the energy efficiency was about 85%, though the depth of discharge was only 40%.