Polarization Admittance Study of Lithium Corrosion in Propylene Carbonate Solutions

Lithium metal is relatively stable in pure propylene carbonate and in pure propylene carbonate solutions containing LiBF₄ and LiCl. Solvent degradation was encountered in the presence of aluminum chloride resulting primarily in the formation of carbon dioxide and chlorohydrins. The proposed mechanism involves reaction of lithium with the chlorohydrins resulting in a relatively high corrosion rate accompanied by hydrogen evolution. Use of the polarization admittance technique produced data in qualitative agreement with weight loss values. Corrosion rates based on polarization data were higher than those based on weight losses. The lack of quantitative agreement indicates that the conditions imposed on the technique were not encountered in this complex environment.