Voltage and Current Transients in Lithium Thionyl Chloride Cells AccompanyingInterrupted Electrolyte Additions

摘要

An investigation was carried out in an attempt to explain the out-of-familyvoltage trace associated with one of the 250 A-h lithium thionyl chloride cells used in batteries for selected Centaur missions. The voltage trace was generated during the manufacturing step where electrolyte is added to the cell. The investigation was carried out in several steps. First, discussions were held with the manufacturer, who was able to suggest theories that were consistent with the observations that were available for review. These theories were later tested in the electrochemical laboratories of The Aerospace Corporation. Using specially constructed cells equipped with reference electrodes, we measured the individual contributions of the anode, cathode, and cell container to the overall voltage transients associated with an interrupted cell filling process. These results validated some of the manufacturer's theories. What had been suggested as a minor contributor to the voltage traces was found by experimentation to be the most important one. That was the contribution of the porous carbon electrode. Our experiments added further support to the earlier conclusion that the out-of-family voltage signature seen in cell Number 474 was not indicative of a problem within the cell.