Abstract: The present invention consists in a rechargeable cell having an anode made from materials in which lithium can be inserted, a cathode and an electrolyte constituted by a solution of a lithium salt in a non-aqueous solvent. The material of said cathode includes at least one substance which is a yellow-green single-phase oxide of lithium and manganese with an orthorhombic crystal structure with the following lattice parameters: a=0.459.+-.0.004 nm, b=0.577.+-.0.004 nm and c=0.281.+-.0.003 nm and containing lithium ions in a molar ratio Li/Mn such that 0.85.ltoreq.Li/Mn.ltoreq.1.10. After a first charge said substance is discharged in two stages of which the higher is at a mean voltage greater than 3.5 volts relative to the lithium.

Abstract: A lithium rechargeable electrochemical cell comprising an anode of pure or alloyed lithium or of lithium-containing carbon, a cathode of metal oxide, and an electrolyte comprising a mixture of aprotic organic solvents and a lithium salt, characterized by the fact that said mixture is made up of:5% to 40% by volume of propylene carbonate;10% to 20% by volume of ethylene carbonate; and50% to 85% by volume of dimethyl carbonate.

Abstract: The invention relates to a positive active material for an electric cell. Such an active material is constituted by a vitreous compound which results from the addition of a small quantity of silica to at least one electrochemically reducible metal oxide. Application to electric cells with non-aqueous electrolyte, the negative electrodes of these cells being based on an alkali or alkali-earth metal.