The Reduction of Sulfuryl Chloride at Teflon‐Bonded Carbon Cathodes

Abstract

Polarization and discharge curves were measured for sulfuryl chloride reduction at Teflon‐bonded carbon cathodes fabricated using a number of different carbon powders. Lithium chloroaluminate was utilized as electrolyte solute. At moderate current densities cathode polarization tends to normalize with respect to Brunauer, Emmett, Teller (BET) surface area of the carbon. Cathode life increases with increased porosity of the electrode. The porosity is required for good accommodation of product . A formulation incorporating both high BET area and porosity was developed and found to provide good electrochemical performance against lithium counterelectrodes. When sulfuryl chloride is reduced at the optimized cathode (against a lithium anode), the main products of reaction are (which is quantitatively deposited within the electrode's pores) and . This suggests the overall cell reaction: . The addition of or to the electrolyte causes decrease or increase of cathode polarization, respectively. This may be taken as evidence that the reduction, at moderate current densities, occurs through a intermediate resulting from heterogeneous decomposition of . Reduction of undissociated may occur at high current densities or after the active area of the electrode is significantly reduced through deposition of product .