AC IMPEDANCE STUDY OF POROUS CARBON COLLECTORS FOR Li/SO2, PRIMARY CELLS

Impedance measurements are used to determine the electrochemically active surface area of Teflon-bonded, porous carbon current collectors which are used in Li/SO2 primary cells. An effective pore radius, pore length, and pore number also result from these measurements. Results are compared to BET measurements. In 0.1 M LiBr/acetonitrile electrolyte, only a small fraction of the BET surface area is electrochemically active.