An electric cell with a non-aqueous electrolyte. The cell includes a positive electrode whose active material is suitable for inserting the negative active material dynamically, a negative electrode whose active material includes at least one alkali metal, and an electrolyte, wherein said positive electrode includes at least one compound whose general formula is MX.sub.4 R.sub.n T.sub.p, where M represents an element chosen from among silicon, germanium, tin and lead, X represents sulphur, selenium or tellurium, R and T represent an element chosen from among copper, silver, manganese, iron, cobalt and nickel, n being greater than or equal to 0 and less than or equal to 4, p being greater than or equal to 0 and less than or equal to 2. The invention is used in connection with button type electric cells.