Studies in lithium oxyhalide cells for downhole instrumentation Use of lithium tetrachlorogallate electrolyte in Li/SOCl2 cells

Lithium/thionyl chloride cells containing lithium tetrachlorogallate electrolyte have been shown to provide improved performance during interrupted use with temperature cycling. In LiAlCl 4 -containing cells, the effect, referred to as the ‘early failure problem’, is profound for temperature cycling above 70 °C and subsequent use at room temperature. This is mitigated when the solute is LiGaCl 4 . Generally, the voltage delay for LiGaCl 4 -containing cells is lower than for cells with lithium tetrachloroaluminate, is more reproducible, and the voltage on load is higher. The reduction of LiAlCl 4 at the lithium electrode under discharge at elevated temperature is suggested as the possible reason for the early failure problem.