Li/SOCI2 Battery Technology: Problems and Solutions

Abstract : This report illustrates the advantages of using a rational transition process when developing an electrochemical power source designed to operate at its limits by summarizing the approach and results based on such a transition philosophy. The thionyl chloride electrolyte system has a complex composition that determines the elementary reactions that occur on discharge. Electroreduction rarely involves free thionyl chloride; rather, adducts with A1c13 and Li undergo electroreduction, preferentially. Modeling the Li/SOCl2 system has contributed significantly to an understanding of battery operation of providing the basis for both the design and understanding of electrode thickness and porosity, catalytic effects, thermal management, and intercell currents. Modeling also guided the development of quality control (QC) procedures and considerations. Li/SOCl2 technology has come a long way since the initial recognition of its value as a battery chemistry. Much of this progress has resulted from efforts to pursue a logical progression of transitions through the R and D cycle. These efforts have elucidated the chemistry of the system, the best design features of cells and modules, the assembly of these cells or modules, and the resultant characteristics of these assemblies. The Li/SOCl2 is used only as an example. Other battery technology developments could benefit from such an approach.