Microelectrode Study of the Lithium/Propylene Carbonate Interface: Temperature and Concentration Dependence of Physicochemical Parameters

Selected physicochemical parameters useful for characterizing the metallic lithium electrode exposed to a lithium perchlorate salt in a propylene carbonate solvent are reported as functions of temperature and salt composition. The advantages of using microelectrodes for the measurements are elucidated. Transport parameters governing the electrolyte‐phase limiting current density are found to be independent of salt composition over a concentration range of interest for lithium batteries. The Li‐Li + reaction is shown to correspond to classic electron‐transfer theory, with a symmetry factor of one‐half, as would be expected for a strongly solvated ionic reactant. Simplified equations are derived that allow one to focus on specific aspects of a lithium thin‐film battery, demonstrating the utility of the measured parameters for engineering design studies.