Ultrahigh voltage mixed valence materials

Abstract

A series of electroactive insertion compounds, LiM.sub.y.sup.II M.sub.z.sup.III Mn.sub.l.sup.III Mn.sub.q.sup.IV O.sub.4 (0<y+z.ltoreq.0.5, y+z+l+q=2), where M=any transition metal or combination of metals, for application in non-aqueous batteries, capacitors, and superconducting materials, are disclosed. These newly synthesized compounds are unique in that they contain at least two mixed valence elements, thereby allowing the reversible intercalation of lithium cations at potentials near 4.7-5.1 V vs. lithium. Also disclosed are novel copper insertion compounds of the formula LiM.sub.y Cu.sub.0.5-y Mn.sub.1.5 O.sub.4 (0.ltoreq.y.ltoreq.0.49), where M=one or more metals or transition metals. Such materials have also been found to be remarkably stable at this voltage upon repeated cycling.

Dependencies are inferred from the claim text.