Electrochemical behaviour of some transition metal oxides in molten dimethylsulphone at 150°C

In view of the possible application in non-aqueous líthium cells operating at relatively high temperatures, molten dimethylsulphone (DMSO₂) has been used as the electrolyte solvent in lithium cells at 150°C. The stability of lithium in molten DMSO₂ has been found to be good as compared with that observed in organic solvents such as propylene carbonate, thus indicating that the Li⁺/Li system can be used as a suitable reference electrode in this medium.The electrochemical behaviour of some transition metal oxides has been investigated in LIClO₄ solutions in molten DMSO₂. The results obtained from voltammetric and chronopotentiometric measurements have shown a satisfactory behaviour for all the cathodic materials tested. Moreover, electrochemical insertion of Li⁺ ions into the crystal lattice of these oxides is a very fast process. Thus molten DMSO₂ appears to be a very interesting organic solvent usable in high energy density non-aqueous lithium cells.