Electrochemical Stability of LiMF6 ( M = P , As , Sb ) in Tetrahydrofuran and Sulfolane

is the current state‐of‐the‐art lithium salt for use in many prototype rechargeable systems. The instability and potential toxicity of has led to the search for new lithium salts. To this end, we investigated the electrochemical stability of and in aprotic organic solvents. Electrochemical studies, conductivity measurements, and open‐circuit stability tests were conducted on in tetrahydrofuran and sulfolane. Cyclic voltammetric studies of were compared with those of and anions. Sb(V) was reduced to Sb(III), and then to Sb(0). was reduced to , while no reduction of was observed. Reduction products of and passivated the glassy carbon electrode, presumably due to precipitation. Peak potentials were observed to shift in the positive direction as a function of concentration. This was accounted for on the basis of a follow‐up chemical reaction.